@MegaTabetha It's not because it's not hot enough but because the oxy torch first oxidises the metal and then blows the oxide off. And stainless steel resists oxidation.
I found out when I was a 17 year old apprentice. A lad told me to burn off a corner of stainless. I was there for ages waiting for it to warm up. Meanwhile all of the lads were having a giggle at my expense. Good times.
A friend who worked a lot in cooking materials told me about these problems more than 20 years ago. He told me that we had a lot less seizure if we used stainless steel of different qualities: A2 screws and A4 nuts for example. But according to him, the most effective solution was a stainless steel screw with a brass nut.
This provided the answer to a problem i had when fitting new hinges to a trailer using stainless steel nylock nuts and SS bolts. About 30% of them seized when fitting them before the nut had been fully tightened, these had to be cut off. I did eventually get the job done but used a lot more nuts and bolts with the wastage. Thank you for the very useful information
Today i prepared to replace some small bolts on my 80 series Landcruiser side steps, I installed some rivnuts and thought i would do the right thing and use new 8mm Stainless Steel bolts to replace the old steel ones, however i will reconsider after watching your (as always) very helpful video. I always use an anti seize. Thank you for this timely video, great information. Glen..... South Australia
Thank you... You saved me from doing a huge mistake... I was about to change all my regular steel bolts for ss one on my truck restoration project... I changed my mind after watching your video.... Bless you.
Ya if you got a rust problem or something, you might want to try a chemical solution to your problem... like a coating, plating or a rust converter. Stainless isn't great for fastening... but it is so pretty... but so is chrome
Great demonstration! I have experienced this many times during my career in industrial machine maintenance. I have found you can usually use a lower grade stainless ( 18-8 ) to achieve good corrosion resistance, and they are far less prone to galling. However, there are applications where this would not be allowed.
I came across this problem in model boat building a number of years ago. Now I either use brass nuts or copper paste and this works well. Interesting video all the same!
Very interesting thank you. Apparently using two different grades of stainless steel for nut & bolt reduces the problem of cold welding. Also working very slowly with clean unbroken threads reduces the friction heat that causes the weld..
Great video. Action Can make a product in an aerosol called AG-90, Anti-Galling lubricant It's also food/pharmaceutical grade (h1) for such a problem. It works a treat.
Yes, using different grades of stainless can help. I've had bolts gall up when using a ratchet spanner in the past, when tightening and undoing them. Obviously if we are on a breakdown we have to remove the bolts as fast as possible, even if it means shearing them off and drilling them out afterwards. Thanks for the comment
Note that the "steel" bolts used here are actually cadmium or zinc plated, as are the nuts. SS should ALWAYS have an anti-sieze if into SS or aluminum. Then you also have to be careful not to over-tighten because the anti-sieze reduces the friction so much. And don't spin SS (or aluminum) so fast. Heat generated by friction will increase chances of gauling. Slow down and lubricate.
At work we tend to use a stainless bolt with a standard steel nut on coal and iron ore conveyors. This way the threads stay cleaner than a steel bolt and it comes apart nice and easy as theres less or no galling
Hello Guys, Thanks a lot for this fruitfull video we can understand that: -Galling appears when we use standard stainless steel, I can see A2 on the bolt -Also increasing the speed mouting is not so good during mounting -Stainless is really well know against fire, this is why it is more and more used in construction We need absolutly to separate standard SS bolts and qualitative SS bolts : -Most of the stainless steel bolts strength are obtained by cold forging and this work is really important -The galling is a fact but the method to make the thread is really important. The thread rolling is important. -Last point and maybe the most important, what is the strength of the SS bolt you used? A2-70? Most of the bolts in industry have poor mechanical strength. It means that you will have many chance to enter in the pastic area of your bolts. All these points are really important against galling! You need only to find a stainless company having screws of high quality like Bumax (www.bumax-fasteners.com). They are really well know against galling and also have created same mechanical properties than steel bolts. Feel free to comment !
I was a marine engineer for almost 50 years and in the mid to late seventies we started using some stainless bolts and nuts on steam lines out on deck instead of B7 or B9 bolts and 2H nuts and it was a nightmare they would always gall even with nickel plated antiseize. On tanker ships loaded with gasoline or crude oil you couldn't use a grinder on deck. In the late 90s we started using stainless again and had very little problems with seizing even with copper plated antiseize something changed dramatically between those years with stainless steel. I'm talking about 316 stainless.
At my shop (well, it’s my boss's shop) we’ve turned threads 5 inches in diameter, both of the mating parts, in stainless. We’ve done these many times. 5” x 12 pitch. This corresponds to a 127mm by about 2mm pitch, for you metric worthies. We’ve jammed threads a few times. If you are real lucky you may get it loose with penetrating oil by slowly working back and forth. Slowly. Heat is the enema here. Other times we’ve machined out the mail member, cleaned up the female threads and made another male part. Expensive fix. The trick seems to be lube oil or anti seize, and CLEAN threads. A tiny speck of sanding grit, like what is used to deburr the entrance / exit of the thread, is the starting point for galling.
You have a knack of choosing interesting practical problems to make videos about. I too have found this problem with SS hardware. I've been told (but never verified) that if you mix SS grades it galls less frequently.
I learned something from this, Thanks ! When I use stainless or brass wood screws I pilot the hole and then run the same size steel screw in to thread the hole. Then replace the steel screw with a stainless or brass one. Stainless & brass screws either strip the Phillips recess, snap the screw or twist the head off when power driven.
You are welcome. Stainless screws are useless, I used them once to make a wooden gate. A week later I needed to adjust the hinges and every one of the heads sheared off! Thanks for the comment 😉
Increíble. Jamás pensé que la tornillería de acero inox presentara tales inconvenientes. Excelente información y además muy útil. Gracias por compartirlo.
Hi, thanks a lot for showing this, you saved me from future disaster. I had used 6mm SS Bolts and nuts on a lathe fixture part of the stand, and did noticed it were tighter than anticipated when I had to remove them. I did however used blue marine grease on them. I will now go and examine them all. I bought them from a stainless fabricating shop in our area, not from a general store, if that could matter for types. I used just spanners in this case.
You are welcome. Not all stainless steel bolts gall, most of the time we can undo them on site- but there is always that one, and as soon as you start to undo it you know it has galled. You don't necessarily need an impact gun to make them gall, I just used that to speed things up. We often get galling nuts/bolts when just using normal spanners. Thanks for the comment
One more top tip firmly stored in the noggin. Have used Stainless in the past but am steering well clear henceforth. Also I must have known once upon a time what a set screw is (I googled it - bolts have threads only so far up the shaft), I can't believe at 58 no one ever told me this, so thanks for the memory jog. As ever UH you are the go to man with all the answers.
I'm glad you have found the video useful. Normally if you ask at the hardware store for fully threaded bolts you will get set screws and the person serving you will not bat an eyelid, but with this video going on RUclips I had to point out the difference or else I would have had a thousand comments saying "that is not a bolt, it is a set screw" etc. Stainless bolts are still fine in many applications as long as you use some anti-seize and are aware that they can gall up. Thanks for the comment
Thanks for the info. I had a bad experience trying to get nylock nut off of a stainless steel bolt and have never attempted to use nylock nuts again. I've been using thread locker instead. Now knowing about galling on stainless, I'll use them again.
Very informative thanks. What would you use for non-marine outdoor environments instead of stainless steel? Also does the grade of stainless steel matter? 316 A4 better than A2 or vice versa when it comes to this problem? Cheers.
You are welcome. Galvanised bolts cab be a good solution for outdoors, or if you want the bolts to look good you could just use stainless steel bolts and apply anti-seize compound as that should prevent the galling. I'm not sure about the different grades, but I believe that if you mix the grades, such as a A4 bolt and a A2 nut the problem is nowhere near as bad. Thanks for the comment
How about stainless nut on regular bolt and regular nut on stainless bolt? Also when using the torch to heat up the stainless does it help to remove the stuck nut?
Thank you. I went out of my way to acquire s/s bolts and nuts for re-installing the rear fenders on my Kenworth. I couldn't understand why these new bolts seized the way they did. I thought it was just super cheap bad foreign made bolts. Now I understand. Subscribed and thumbs up.
No, I do not think so. I think galling is only a problem with stainless on stainless, even using two different grades of stainless can help prevent it, such as an A4 bolt and an A2 nut. Thanks for the comment
What about stainless bolts in a aluminum moped block? I just finnished doing a rebuild and I used stainless allen bolts. The thread is not all the way its lenght
Can't gallong be prevented or mitigated by threading the nut on (or the bolt into) at a very slow speed so as to prevent heat build up due to friction ?
great video. i didnt know you couldnt burn off stainless. what do you do if you cant get a grinder in at it. why does the stainless siese up like that . is it because its soft and kinks the threads and crossthreads
Thanks, I think it's something to do with the bolts threads being rolled to form them and the nut threads being cut, if you Google it there will be a lot of info about it. Yes, in the past I have had to cut bolts off with a grinder or even a hacksaw because someone has used stainless bolts, but to be fair they probably thought they were making it easier for next person- not harder. Thanks for the comment
I found this interesting but it didn't go far enough. I was a maintenance tech for 7 McDonald's restaurants for over 20 years and encountered a nightmare when the self-gapping clam-shell grills came into use. The upper platen operated at 425 degrees with a stepper motor and band pulley system to adjust from bacon to McRibb meat by computer. There was nothing BUT stainless fasteners in that mini oven. The adjustment blocks were fine thread bolts into machined bases. After ruining several under warranty, I discover a stick of copper-based anti-seize ( Locktite?)at my fastener dealer rated at 800 degrees. Problem solved. As to galling, part of the high cost of stainless bolts is the threading process. If the cutting gets rushed and the tooling dull it can tear the thread apex and the nut will grab the tear and roll up a (B-all that causes the "Gall". Other bolts are threaded by roll-pressing the threads and then heat treating.
A product called Neolube is just right for this. Graphite in isopropyl alcohol. Two thin coats on both threads. Remove and recoat each time. Graphite doesn't care about temperature.
Excellent! I was wondering why I have had galling issues in the past specifically with SS bolts and Nylock nuts while working on my Motorcycle - now I know! Cheers!
So how would you cut it off is there any way to? Apart from a drill or grinder. Like a Tig welder or something. What would get the metal hot enough to burn? How do they cut stainless steel into shapes?
I’ve had to use a hack saw in the past, but a grinder will work. Stainless steel can be cut on a laser cutter or with a plasma cutter, it just won’t cut using oxygen and acetylene. Thanks for the comment 👍
A seemingly `simple' video, but is so informative. It demolishes my assumption and prejudice that "stainless steel is always better". Despite rusting and making things look unattractive, it may be better for me to live with this than dealing with a seized SS bolt.
I am a design engineer by trade and don't profess to know the hands on stuff like yourself but when design stainless assemblies I would mix the grades of stainless ie 300 grade (austenitic st.stl) nut with 400 grade (Martensitic st.stl) bolt. This dissimilar combination worked pretty well on gas turbine bits. I didn't realise that you couldn't burn out stainless but it is full of Nickel and chrome so pretty good at resisting heat. Another point is that 300 grade stainless is weak as it comes....it's about as good as super cheap Chinese bolts, saying that 400 grade can be heat treated up to the equivalent of 8,8 bolts maybe more.....we use it for compressor blades on gas turbines so it's tough and good in tensile strength.
Using different grades of stainless is supposed to help prevent galling, although I can't confirm that is true as I have not tested it. Thanks for the comment 😉
Thanks for a great tip! I had no idea that stainless could seize up like this, I'll be thinking twice before using stainless next time if it's not absolutely necessary!
Happened to me yesterday using SS sheet metal screws. The screws seized before going all the way in the sheet metal and I stripped the screw heads trying to drive them in. I even had the holes drilled larger than recommended and they still seized. Had I seen this video beforehand I would never have used them.
A wipe of oil will prevent this. We usually assemble stainless fasteners with a bit of moly grease and we never see any problems. The trouble we do see is in very old installations where stainless bolts have sat in tapped aluminium holes for 20 years or more. The aluminium corrodes, egged on by the less reactive stainless, and it locks up as tight as tight can be. In fairness the same or worse would happen to carbon steel. If you want a real nightmare, bolt copper to aluminium and leave it near the sea, it’ll rot like a pear in a cesspit.
I've been a mechanic a long time, and just discovered this stainless galling problem. I ran a bolt once, and couldn't get it off without almost breaking a wrench. Of course it was in an extremely difficult area to access. And I didn't even know you couldn't burn stainless with a torch. Great video. Interesting comment below confirms that it was partly due to using nyloc nuts.
It depends, I used Nylocks as they create a lot of friction and so they can gall up really quickly. I have had M16 stainless nuts and stainless bolts gall up on a steam valve (not Nylocks), which I had to saw off using a hacksaw. The machine that is pictured in the video (with the Milwaukee ratchet) also galls up when undoing the stainless bolts- using a regular ratchet spanner. Thanks for the comment
With the nylock nut on the s.s. bolt: Did the sharp threads of the bolt cut up the nylon threads, then dig into the nut itself, causing it to seize (gall)? If not, what was the proximate cause that made it seize?
Just had to return to this video after thinking it over. Galling is indeed a problem with SS fittings, particularly with locking nuts. But as a problem it usually only becomes apparent with the larger sized screws. I've used small ones for years with nary a problem. Even with the larger ones, if the thread is properly lubricated and you proceed with hand tools, you're unlikely to have a problem. But if you do feel it tightening up, you want to reverse and not force the issue, then either use your taps and dies to clean up the thread, or replace the nut and bolt. The problem with SS is that any heat generated is not as quickly dispersed as with other steels, leading to tightness between the two components. And running a locknut repeatedly on and off with a power tool is guaranteed to generate a significant amount of heat. In short, most of the "problem" has been artificially generated.
Stainless nylocs on stainless screws equals disaster. For many years I worked in a marine environment where it was necessary to use stainless fixings - beacons at sea,marina pontoons etc. If nylocs had been used ,you could virtually guarantee that one of the fixings would've "picked up" and have to be cut off. This is a ball ache ashore but a nightmare stuck on a rock ,miles from land. Blessed be the advent of the battery grinder and thin cutting discs!. Anti-galling paste is of some help but not guaranteed to work .In all the years I did it, I never had a plain nut come loose provided it was correctly used.In my view, stainless nylocs are the work of the devil.
Wondering the same thing as rivercarper01 - is it something specific about nylock nuts that makes it worse? I always thought any stainless-on-stainless had a chance to gall and sieze.
We fit nyloc s/s nuts to s/s bolts and it’s a nightmare. Cutting off every 5 out of 20. Just a complete pain, yet the supplier designs them that way so we are kinda stuck with it.
@rivercarper01 We have a large solar panel array on our ranch. Something like 48 pivot points each with a stainless bolt and nut that has to be loosened and tightened twice a year for sun position adjustment. 90% of them were seized after the first couple of years. These are conventional nuts. These were always adjusted by using hand wrenches. Gonna' have to research some alternative soon.
Good video, nice to know. I recently replaced the bolts and nuts on the roof rack of my truck for stainless steel since the steel ones that was on there had almost corroded away to the point of no longer being able to keep the thing together (this truck sits outside next to the ocean 24/7 and corrosion is a massive pain the ass). I wondered why they don't just do stainless steel on all the bolts of the truck, apart from cost I guess this answers my question. I'm still happy that I swapped those to stainless though, since I never have to undo/redo those bolts so seizing won't bother me so much and now, with the stainless bolts and nuts, it should basically last for the lifetime of the roof rack and/or truck.
Couple questions come to mind; are stainless steel bolts more of a one time use thing? What if you slowly loosen/tighten nut every to avoid much heat from generating preventing galling?
The impact driver is a Kielder, I keep it in the back of the van for emergencies (its a great little impact wrench) ruclips.net/video/2jlSqjpwZwY/видео.html Thanks for the comment
I'm not sure, as it's not something I normally do. Most of the time we use steel nuts and bolts and just apply anti-seize compound. Worst case scenario, is that you either have to cut the bolts off using a grinder/hacksaw or gas axe (depending on where it is). Stainless and steel bolts should not gall, but there might be corrosion issues, a bit like if you put steel wool near a stainless steel sink - it can make it rust.
Interesting video, I'd never heard of stainless galling before. I've rebuilt several bicycles using stainless fasteners, and not encountered any problems like this - maybe screwing into aluminium and/or using copper grease has prevented problems.
Not sure, it could be something to do with the chromium content. Apparently if you use different grades of stainless such as a A4 bot and a A2 nut the galling problem is not as bad- or you can apply some anti-seize compound. Thanks for the comment
Assuming the issue a user may be trying to avoid, by using Stainless Steel bolts with SS nuts, is the nut rusting to the bolt, rather than the nut or bolt rusting to whatever is being bolted; would using a non-SS steel nut on an SS bolt, or SS nut on a non-SS bolt be a non-galling solution?
I would imagine that a steel nut on a stainless bolt would be fine, especially if the bolt was coated with some copper anti-seize compound. Thanks for the comment
Well I for one don’t mind admitting I’d never heard of this. As you said, I thought SS was the better choice nearly always (actually, always) Thanks for the video 👍
Very good information, thanks. So does this problem occur only when using stainless steel Nyloc? The Nyloc causes much friction if you drive it too fast. I always use only hand tools or very slow rpms when fastening stainless steel Nylocs.
No, I only used Nylocks and the impact wrench to speed up the demonstration. The washing machine rollers often gall up, and normally the bolts are tightened or undone with a ratchet spanner. I went to change a 2" steam valve a few weeks back and someone had used stainless steel nuts and bolts on that and they galled up (you can't tighten or undo them with an impact wrench as you can't get it in because of the flanges). Thanks for the comment
What a lot of people don't know is that oxyacetlene torches work by first oxidising the workpiece and then blowing that oxide off. And stainless steel resists oxidation... Quick question though, would you treat stainless steel bolts/screws the same as nyloc nuts (i.e. just one use) or can you replace on removal without future issues?
It depends what the threads look like when the bolts are removed. If the threads look damaged in any way I bin them and install new ones. Thanks for the comment
I don't think so, I believe it's only a problem with stainless on stainless, even using two different grades of stainless such as A4 and A2 can help reduce the problem. Thanks for the comment
If one does indeed have a galled ss bolt, what is the only/best method to remove it? If the two parts have married and became one, is it useless to even try to 'break it free' by unscrewing it?
Thanks for that, I ride my bike 365 to and from work, I have gradually changed most of my bolts to stainless but there's not much stainless into stainless, most into alloy. Should be okay?
great information! i believe there are grades that exist that reduce the galling and also avoiding use of power tools helps a great deal too, couple with some lubricant if possible.
Anti-seize will definitely help, also using grade A4 bolts and A2 nuts can help reduce galling. Thanks for the comment
6 лет назад
Thank you very much I did not know stainless steel nuts gall or that you cannot burn them off. Why is it that they push stainless bolts more than galvanised ones?
You are welcome. In some situations stainless bolts and nuts are better, galling can be eliminated in a lot of cases by using a suitable anti-seize compound. Thanks for the comment
6 лет назад
Ultimate Handyman If you did not know they galled and did not know that anti seize compounds are used they are not much good.
You've overlooked the lubricating done by the zinc plating. No threads are designed for repeated use of power tools, which means the bolts are not being used as intended. Perhaps they are the wrong grade of SS bolt?
The impact wrench was only used to show how quickly it can occur. On site we often come across galling, even when using spanners. Thanks for the comment
Don't believe SS comes "graded" in different grades for a given alloy ( 304 , 316). That said, each alloy has its own strength characteristics but I don't "think" a specific SS alloy bolt or nut is available in a variety of stength grades like carbon steel bolts.
I have noticed this problem before, if possible I try to apply a little Tallow Fat to the Stainless Bolt, also I use A4 Stainless instead of the weaker A2 grade. One golden rule that I cannot stress enough is "KILL THE SPEED" never ever wind stainless bolts together at speed using powered ratchets, it is the speed that can cause galling. Always wind them together slowly, it takes longer but its much safer. Stainless does not conduct heat away like steel will, this is why you only need about a third of the power to weld the stuff, so when driving it at speed, friction heating can start off the galling. It is Horses for courses really, sometimes only stainless will do a particular job. When cutting, welding or grinding stainless always wear a mask to guard against harmful hexavalent chromium emissions, lest you get lung cancer.
very very useful info, would stainless bolts into steel captive nuts do the same? i was thinking of using ss bolts to replace some of the grotty steel ones on my classic car for the removable service stuff what type of 'dress up ' bolts would you recommend, chromed steel? thanks, and thanks for the great info.
Stainless bolts into steel nuts should be fine, even different grades of stainless, such as using A4 bolts with A2 nuts can help to reduce the problem. If you use a good anti-seize compound it can prevent the galling from occurring, but please be aware that stainless bolts are also not as strong as steel bolts (something to consider on vehicles). Thanks for the comment
In my work I use stainless steel bolts and nuts ONLY once. Especially where there is a lot of heat involved. The only real benefit is that these do not rust, but other than that they offer absolutely no advantage at all. Once I loosen a stainless nut or bolt it gets replaced.
I would not risk it to be honest. I'd just use steel bolts, preferably BZP or black phosphate coated and use some decent anti-seize compound. Thanks for the comment
Interesting. Thanks. If a non nylock nut is used, will it still gall up? What causes the galling? Heat? Also, if the nut is tightened by hand (rather than using a drill) then will the nut come off easily in future. Many thanks.
Nylocks make the galling happen quicker as it is caused by friction. If you Google for galling there are lots of pages that explain why it happens much better than I can. It still happens if you tighten or loosen the nut by hand, I have had it happen to me several times when just using a ratchet spanner. Thanks for the comment
Worked in the food industry for a couple decades, stainless is a way of life in the food industry. Never Seize will keep a stainless nut/bolt from seizing for a while, but does wear off if constantly taken apart and put back together. IF, you are where you don't have to have stainless but only have stainless of either a nut or bolt, a regular steel nut or bolt won't seize with stainless. Any good quality lube will also keep SS from galling for at least the first time, but when they get tight they will gall.
So, cutting ss is a different animal. Cut off wheel (disc) works if it fits in the space, but sprays chips (future rust stains) everywhere. But using a hacksaw (or just a hacksaw blade in vise grips cutting on the "pull" stroke) works pretty well. If you happen to be cutting thin sheet metal, you pretty much have to use a fine tooth blade. But whenever the ss is thick enough, use an 18, or even 14tpi. Always use hss blades. A fine tooth blade will only polish and further work harden ss. A coarse blade is necessary bc you need to RIP THROUGH the metal. Make every stroke count. If your coarse blade is not cutting, either it is dull, or you are not being aggressive enough with it. Cheap or tubular hacksaw frames will definitely work against you here. If you are just grabbing a blade in your vise grips, wear leather gloves, clamp onto the toothed side of the blade, and cut on the pull stroke. Sometimes you can even clamp two blades together to stiffen them (clogs faster, though). Your channel and videos are fantastic. You saw a need to present some truth, vs the epidemic of "amateur hour" videos, and filled it. Thank You
Not a Stainless Steel story, but along the same lines. We had aluminum "saw guides" that we had to put shims on for adjusting board sizes. We used 1/4 inch, hardened, grade 8 steel bevel head bolts that went into a tapped hole in the aluminum guide (good aircraft grade aluminum). Even with just snugging the bolts they would need a cheater pipe on the allen key, and POP loose. They were so tight that I would put a rag over the allen so it didn't launch like a bullet if it slipped out of the allen hole. Grease or anti-seize wouldn't help. Once they popped loose they would come right out with no thread damage. We had hundreds of these to do on a size change, and 95% were like that. We ended up getting all brass screws and never had a problem again. So in conclusion, for some reason those hardened bolt and the aluminum did not like each other.
If you need to use stainless you can buy ready silver plated that avoid this galling effect (they are not the cost hike that silver plating suggests). Otherwise I would use AG-90 Lubricant. If naked stainless is a must then try using nut at A2 grade with an A4 bolt. Its not addressed here but the one thing that many don't appreciate is you can't just swap steel for stainless and get the same preload on the clamping surfaces for same set torque. Generally stainless gives *much* lower preload ...i.e. If you simply swap for stainless and torque up to the same then you risk whatever assembly you have just fastened falling apart (subject of course to its max design load and loading conditions.). Can be dangerous! Be careful about application.
Thank you for this video. How did I get to the age of 71.5 years without knowing that stainless steel bolts cannot be cut by an oxyacetylene torch? Sheesh! My face is red! Again, thank you for this video. Subscribed.
Yes, it's tensile strength is not as strong as a steel bolt, but for example when drilling stainless steel it can be harder to drill as it can work harden etc. Thanks for the comment
If you apply grease to the threads, is there any difference....?......as I apply some form of grease to every bolt or screw with my motorcycle refurbishment...
his combination on stainless, power tools and the lock nuts makes friction, the paste helps but that combo is the problem, stainless just wants to weld itself together, avoid using power tools would be the first and use plain nuts, not locknuts, then you probably wont have any issues.
Applying anti-seize compound can help. I've had bolts that have galled up when removing them with a ratchet spanner, but they have often been a machine that is heated, so that could contribute to the galling. Thanks for the comment
Thanks for this excellent and informative video. I seem to remember that a combination of a brass nut and stainless screw is recommended for some applications.
Wow I didn't know you couldn't burn off stainless steel. You learn something new everyday👍👍
I only found out myself a few years ago ;-)
Thanks for the comment
@MegaTabetha
It's not because it's not hot enough but because the oxy torch first oxidises the metal and then blows the oxide off. And stainless steel resists oxidation.
Ditto. Never to old to learn.👍
Plasma cuts it just fine.
I found out when I was a 17 year old apprentice. A lad told me to burn off a corner of stainless. I was there for ages waiting for it to warm up. Meanwhile all of the lads were having a giggle at my expense. Good times.
A friend who worked a lot in cooking materials told me about these problems more than 20 years ago. He told me that we had a lot less seizure if we used stainless steel of different qualities: A2 screws and A4 nuts for example. But according to him, the most effective solution was a stainless steel screw with a brass nut.
Thanks for the comment ;-)
This provided the answer to a problem i had when fitting new hinges to a trailer using stainless steel nylock nuts and SS bolts. About 30% of them seized when fitting them before the nut had been fully tightened, these had to be cut off. I did eventually get the job done but used a lot more nuts and bolts with the wastage. Thank you for the very useful information
You are welcome
Thanks for the comment
Today i prepared to replace some small bolts on my 80 series Landcruiser side steps, I installed some rivnuts and thought i would do the right thing and use new 8mm Stainless Steel bolts to replace the old steel ones, however i will reconsider after watching your (as always) very helpful video. I always use an anti seize. Thank you for this timely video, great information. Glen..... South Australia
You are welcome ;-)
As long as you use anti-seize there should not be a problem, especially if the rivnuts are steel.
Thanks for the comment
Thank you... You saved me from doing a huge mistake... I was about to change all my regular steel bolts for ss one on my truck restoration project... I changed my mind after watching your video.... Bless you.
Thanks for the comment ;-)
You can still do what you wanted with the s/s fasteners to prevent corrosion.
Do not us stainless for structural connections on automotive. 10.9 grade steel.
Ya if you got a rust problem or something, you might want to try a chemical solution to your problem... like a coating, plating or a rust converter. Stainless isn't great for fastening... but it is so pretty... but so is chrome
Great demonstration! I have experienced this many times during my career in industrial machine maintenance. I have found you can usually use a lower grade stainless ( 18-8 ) to achieve good corrosion resistance, and they are far less prone to galling. However, there are applications where this would not be allowed.
Thanks for the comment
I came across this problem in model boat building a number of years ago. Now I either use brass nuts or copper paste and this works well. Interesting video all the same!
Thanks for the comment ;-)
I'm off to work for the day, I'll answer comments on my return !
I hope everyone has a great Sunday ;-)
Very interesting thank you. Apparently using two different grades of stainless steel for nut & bolt reduces the problem of cold welding. Also working very slowly with clean unbroken threads reduces the friction heat that causes the weld..
Would it be a problem if u used a socket and ratchet as to oppose a wrench gun ? Cheers
Great video. Action Can make a product in an aerosol called AG-90, Anti-Galling lubricant It's also food/pharmaceutical grade (h1) for such a problem. It works a treat.
Yes, using different grades of stainless can help.
I've had bolts gall up when using a ratchet spanner in the past, when tightening and undoing them. Obviously if we are on a breakdown we have to remove the bolts as fast as possible, even if it means shearing them off and drilling them out afterwards.
Thanks for the comment
They still gall up using a ratchet spanner, but the impact wrench makes them gall up much faster.
Thanks for the comment
Note that the "steel" bolts used here are actually cadmium or zinc plated, as are the nuts. SS should ALWAYS have an anti-sieze if into SS or aluminum. Then you also have to be careful not to over-tighten because the anti-sieze reduces the friction so much. And don't spin SS (or aluminum) so fast. Heat generated by friction will increase chances of gauling. Slow down and lubricate.
Very interesting ... I've never seen anyone actually try and oxy stainless but it was fun watching the attempt. Cheers for the demonstration and info.
I'm glad you found the video interesting ;-)
Thanks for the comment
Wish I had known this years ago! My engineering course at college missed this one back in 1986! Potential disasters averted. Thank you.
I’m glad you found the video useful
Thanks for the comment 👍
At work we tend to use a stainless bolt with a standard steel nut on coal and iron ore conveyors. This way the threads stay cleaner than a steel bolt and it comes apart nice and easy as theres less or no galling
Thanks for the comment ;-)
Hello Guys,
Thanks a lot for this fruitfull video we can understand that:
-Galling appears when we use standard stainless steel, I can see A2 on the bolt
-Also increasing the speed mouting is not so good during mounting
-Stainless is really well know against fire, this is why it is more and more used in construction
We need absolutly to separate standard SS bolts and qualitative SS bolts :
-Most of the stainless steel bolts strength are obtained by cold forging and this work is really important
-The galling is a fact but the method to make the thread is really important. The thread rolling is important.
-Last point and maybe the most important, what is the strength of the SS bolt you used? A2-70?
Most of the bolts in industry have poor mechanical strength. It means that you will have many chance to enter in the pastic area of your bolts.
All these points are really important against galling!
You need only to find a stainless company having screws of high quality like Bumax (www.bumax-fasteners.com). They are really well know against galling and also have created same mechanical properties than steel bolts.
Feel free to comment !
does it occur if only one, nut or screw is stainless and other is mild?
No, this only occurs with stainless on stainless 👍
I was a marine engineer for almost 50 years and in the mid to late seventies we started using some stainless bolts and nuts on steam lines out on deck instead of B7 or B9 bolts and 2H nuts and it was a nightmare they would always gall even with nickel plated antiseize. On tanker ships loaded with gasoline or crude oil you couldn't use a grinder on deck. In the late 90s we started using stainless again and had very little problems with seizing even with copper plated antiseize something changed dramatically between those years with stainless steel. I'm talking about 316 stainless.
Thanks for the comment ;-)
At my shop (well, it’s my boss's shop) we’ve turned threads 5 inches in diameter, both of the mating parts, in stainless. We’ve done these many times. 5” x 12 pitch. This corresponds to a 127mm by about 2mm pitch, for you metric worthies. We’ve jammed threads a few times. If you are real lucky you may get it loose with penetrating oil by slowly working back and forth. Slowly. Heat is the enema here. Other times we’ve machined out the mail member, cleaned up the female threads and made another male part. Expensive fix. The trick seems to be lube oil or anti seize, and CLEAN threads. A tiny speck of sanding grit, like what is used to deburr the entrance / exit of the thread, is the starting point for galling.
Thanks for the comment
You have a knack of choosing interesting practical problems to make videos about.
I too have found this problem with SS hardware. I've been told (but never verified) that if you mix SS grades it galls less frequently.
Thanks for the comment
I learned something from this, Thanks ! When I use stainless or brass wood screws I pilot the hole and then run the same size steel screw in to thread the hole. Then replace the steel screw with a stainless or brass one. Stainless & brass screws either strip the Phillips recess, snap the screw or twist the head off when power driven.
You are welcome.
Stainless screws are useless, I used them once to make a wooden gate. A week later I needed to adjust the hinges and every one of the heads sheared off!
Thanks for the comment 😉
Increíble. Jamás pensé que la tornillería de acero inox presentara tales inconvenientes. Excelente información y además muy útil. Gracias por compartirlo.
De nada
Gracias por el comentario
Thanks. Something I hadn't realised. What happens to mild steel nuts on stainless bolts?
Mild steel on stainless should not be a problem, it's only stainless on stainless that causes the problem.
Thanks for the comment
Hi, thanks a lot for showing this, you saved me from future disaster. I had used 6mm SS Bolts and nuts on a lathe fixture part of the stand, and did noticed it were tighter than anticipated when I had to remove them. I did however used blue marine grease on them. I will now go and examine them all. I bought them from a stainless fabricating shop in our area, not from a general store, if that could matter for types. I used just spanners in this case.
You are welcome.
Not all stainless steel bolts gall, most of the time we can undo them on site- but there is always that one, and as soon as you start to undo it you know it has galled. You don't necessarily need an impact gun to make them gall, I just used that to speed things up. We often get galling nuts/bolts when just using normal spanners.
Thanks for the comment
One more top tip firmly stored in the noggin. Have used Stainless in the past but am steering well clear henceforth. Also I must have known once upon a time what a set screw is (I googled it - bolts have threads only so far up the shaft), I can't believe at 58 no one ever told me this, so thanks for the memory jog. As ever UH you are the go to man with all the answers.
I'm glad you have found the video useful. Normally if you ask at the hardware store for fully threaded bolts you will get set screws and the person serving you will not bat an eyelid, but with this video going on RUclips I had to point out the difference or else I would have had a thousand comments saying "that is not a bolt, it is a set screw" etc.
Stainless bolts are still fine in many applications as long as you use some anti-seize and are aware that they can gall up.
Thanks for the comment
Thanks for the info. I had a bad experience trying to get nylock nut off of a stainless steel bolt and have never attempted to use nylock nuts again. I've been using thread locker instead. Now knowing about galling on stainless, I'll use them again.
They are a nightmare when they do gall up, but a bit of anti-seize should prevent that.
Thanks for the comment
Very informative thanks. What would you use for non-marine outdoor environments instead of stainless steel? Also does the grade of stainless steel matter? 316 A4 better than A2 or vice versa when it comes to this problem? Cheers.
You are welcome. Galvanised bolts cab be a good solution for outdoors, or if you want the bolts to look good you could just use stainless steel bolts and apply anti-seize compound as that should prevent the galling. I'm not sure about the different grades, but I believe that if you mix the grades, such as a A4 bolt and a A2 nut the problem is nowhere near as bad.
Thanks for the comment
brass nuts with the stainless bolts works very well indeed
Pat19eighty4 zink coated or galvanized..oil base paint or grease works as long as you re apply every 6 months in high humidity conditions
How about stainless nut on regular bolt and regular nut on stainless bolt? Also when using the torch to heat up the stainless does it help to remove the stuck nut?
They will be fine, it's only stainless on stainless that causes the problem ;-)
@@ultimatehandyman So I can use stainless bolts on an engine to hold the exhaust manifold on aluminum heads?
@@judgedredd8876 You could do, but I'd use steel to be honest- just use a good ceramic based anti-seize compound!
@@ultimatehandyman Thank you!
Thank you. I went out of my way to acquire s/s bolts and nuts for re-installing the rear fenders on my Kenworth. I couldn't understand why these new bolts seized the way they did. I thought it was just super cheap bad foreign made bolts. Now I understand. Subscribed and thumbs up.
You are welcome
Thanks for the comment
Would there be an issue if a stainless nut is used with a steel bolt/steel nut with stainless bolt?
No, I do not think so. I think galling is only a problem with stainless on stainless, even using two different grades of stainless can help prevent it, such as an A4 bolt and an A2 nut.
Thanks for the comment
You have just saved me a few quid as I was about to install some stainless bolts on my motorcycle refurb. Thanks for posting
You are welcome
Thanks for the comment ;-)
What about stainless bolts in a aluminum moped block? I just finnished doing a rebuild and I used stainless allen bolts. The thread is not all the way its lenght
It should be fine. Problems only occur with stainless steel bolts, when they are used on something else made from stainless steel 👍
Quite a few learning's from today's video. Thank you sir
You are welcome
Thanks for the comment
Can't gallong be prevented or mitigated by threading the nut on (or the bolt into) at a very slow speed so as to prevent heat build up due to friction ?
It can, but it does not guarantee to prevent it from happening.
Thanks for the comment
What if you use a stainless nyloc on a steel bolt or vice a versa
That will be fine, it is only stainless on stainless that causes the problem.
Thanks for the comment ;-)
great video. i didnt know you couldnt burn off stainless. what do you do if you cant get a grinder in at it. why does the stainless siese up like that . is it because its soft and kinks the threads and crossthreads
Thanks, I think it's something to do with the bolts threads being rolled to form them and the nut threads being cut, if you Google it there will be a lot of info about it.
Yes, in the past I have had to cut bolts off with a grinder or even a hacksaw because someone has used stainless bolts, but to be fair they probably thought they were making it easier for next person- not harder.
Thanks for the comment
I found this interesting but it didn't go far enough. I was a maintenance tech for 7 McDonald's restaurants for over 20 years and encountered a nightmare when the self-gapping clam-shell grills came into use. The upper platen operated at 425 degrees with a stepper motor and band pulley system to adjust from bacon to McRibb meat by computer. There was nothing BUT stainless fasteners in that mini oven. The adjustment blocks were fine thread bolts into machined bases. After ruining several under warranty, I discover a stick of copper-based anti-seize ( Locktite?)at my fastener dealer rated at 800 degrees. Problem solved. As to galling, part of the high cost of stainless bolts is the threading process. If the cutting gets rushed and the tooling dull it can tear the thread apex and the nut will grab the tear and roll up a (B-all that causes the "Gall". Other bolts are threaded by roll-pressing the threads and then heat treating.
Thanks for the comment
A product called Neolube is just right for this. Graphite in isopropyl alcohol. Two thin coats on both threads. Remove and recoat each time. Graphite doesn't care about temperature.
Is the solution to use a spanner or wrench to fasten the nut, rather than a power tool? A lot of intersting info in the video, thank you.
They can still gall up when using spanners, a good anti-seize compound can help though.
Thanks for the comment
Excellent! I was wondering why I have had galling issues in the past specifically with SS bolts and Nylock nuts while working on my Motorcycle - now I know! Cheers!
You are welcome
Thanks for the comment
So how would you cut it off is there any way to? Apart from a drill or grinder. Like a Tig welder or something. What would get the metal hot enough to burn? How do they cut stainless steel into shapes?
I’ve had to use a hack saw in the past, but a grinder will work. Stainless steel can be cut on a laser cutter or with a plasma cutter, it just won’t cut using oxygen and acetylene.
Thanks for the comment 👍
Thank you for the demonstration! That stainless bolt galled surprisingly fast.
You are welcome
Yes, it surprised me how quickly that galled up!
Thanks for the comment
even a standard SS nut would gall easily by just using your hand to thread it on...
A seemingly `simple' video, but is so informative. It demolishes my assumption and prejudice that "stainless steel is always better". Despite rusting and making things look unattractive, it may be better for me to live with this than dealing with a seized SS bolt.
Absolutely!
Thanks for the comment ;-)
wow, you probably just saved me a lot of time and money, thank you
Thanks. So what would one do to remove said stainless steel bolt?
You would have to cut it off using a grinder or hacksaw etc.
If the bolt has broken in a hole it would have to be drilled out.
Thanks for the comment
This is a good lesson for ignorants. Naturaly I have learned this in my working days in the Shipyard.
👍
I am a design engineer by trade and don't profess to know the hands on stuff like yourself but when design stainless assemblies I would mix the grades of stainless ie 300 grade (austenitic st.stl) nut with 400 grade (Martensitic st.stl) bolt. This dissimilar combination worked pretty well on gas turbine bits. I didn't realise that you couldn't burn out stainless but it is full of Nickel and chrome so pretty good at resisting heat. Another point is that 300 grade stainless is weak as it comes....it's about as good as super cheap Chinese bolts, saying that 400 grade can be heat treated up to the equivalent of 8,8 bolts maybe more.....we use it for compressor blades on gas turbines so it's tough and good in tensile strength.
Using different grades of stainless is supposed to help prevent galling, although I can't confirm that is true as I have not tested it.
Thanks for the comment 😉
Thanks for a great tip!
I had no idea that stainless could seize up like this, I'll be thinking twice before using stainless next time if it's not absolutely necessary!
I didn't know until I worked on a few machines where the stainless bolts used to shear off for fun!
Thanks for the comment
I've been wasting money and causing more problems for myself. Thank you for the information.
Happened to me yesterday using SS sheet metal screws. The screws seized before going all the way in the sheet metal and I stripped the screw heads trying to drive them in. I even had the holes drilled larger than recommended and they still seized. Had I seen this video beforehand I would never have used them.
Thanks for the comment ;-)
A wipe of oil will prevent this. We usually assemble stainless fasteners with a bit of moly grease and we never see any problems.
The trouble we do see is in very old installations where stainless bolts have sat in tapped aluminium holes for 20 years or more. The aluminium corrodes, egged on by the less reactive stainless, and it locks up as tight as tight can be. In fairness the same or worse would happen to carbon steel.
If you want a real nightmare, bolt copper to aluminium and leave it near the sea, it’ll rot like a pear in a cesspit.
Thanks for the comment ;-)
Nice demo but why would you run a nut up and down the bolt. What's wrong with just tightening it up once?
That was done just to show how quickly stainless can gall up. We get them galling all the time at work, even when just using spanners!
Damn, I never would have even begun to guess stainless acted this way. You learn something new every day
Thanks for the comment
I've been a mechanic a long time, and just discovered this stainless galling problem. I ran a bolt once, and couldn't get it off without almost breaking a wrench. Of course it was in an extremely difficult area to access. And I didn't even know you couldn't burn stainless with a torch. Great video. Interesting comment below confirms that it was partly due to using nyloc nuts.
Thanks for the comment ;-)
Is it just nylocs that are an issue or will regular stainless nuts on stainless bolts have the same problem
It depends, I used Nylocks as they create a lot of friction and so they can gall up really quickly. I have had M16 stainless nuts and stainless bolts gall up on a steam valve (not Nylocks), which I had to saw off using a hacksaw. The machine that is pictured in the video (with the Milwaukee ratchet) also galls up when undoing the stainless bolts- using a regular ratchet spanner.
Thanks for the comment
Robert B when there is any resistance you have galling
With the nylock nut on the s.s. bolt: Did the sharp threads of the bolt cut up the nylon threads, then dig into the nut itself, causing it to seize (gall)? If not, what was the proximate cause that made it seize?
The stainless galled together. We get this on site regularly, even if a impact wrench has not been used.
Thanks for the comment
Just had to return to this video after thinking it over. Galling is indeed a problem with SS fittings, particularly with locking nuts. But as a problem it usually only becomes apparent with the larger sized screws. I've used small ones for years with nary a problem. Even with the larger ones, if the thread is properly lubricated and you proceed with hand tools, you're unlikely to have a problem. But if you do feel it tightening up, you want to reverse and not force the issue, then either use your taps and dies to clean up the thread, or replace the nut and bolt. The problem with SS is that any heat generated is not as quickly dispersed as with other steels, leading to tightness between the two components. And running a locknut repeatedly on and off with a power tool is guaranteed to generate a significant amount of heat. In short, most of the "problem" has been artificially generated.
Thanks for the comment ;-)
Stainless nylocs on stainless screws equals disaster. For many years I worked in a marine environment where it was necessary to use stainless fixings - beacons at sea,marina pontoons etc. If nylocs had been used ,you could virtually guarantee that one of the fixings would've "picked up" and have to be cut off. This is a ball ache ashore but a nightmare stuck on a rock ,miles from land. Blessed be the advent of the battery grinder and thin cutting discs!. Anti-galling paste is of some help but not guaranteed to work .In all the years I did it, I never had a plain nut come loose provided it was correctly used.In my view, stainless nylocs are the work of the devil.
I can imagine that being a nightmare job- it's hard enough when you are working on a site and it happens!
Thanks for the comment
Wondering the same thing as rivercarper01 - is it something specific about nylock nuts that makes it worse? I always thought any stainless-on-stainless had a chance to gall and sieze.
We fit nyloc s/s nuts to s/s bolts and it’s a nightmare. Cutting off every 5 out of 20. Just a complete pain, yet the supplier designs them that way so we are kinda stuck with it.
@rivercarper01 We have a large solar panel array on our ranch. Something like 48 pivot points each with a stainless bolt and nut that has to be loosened and tightened twice a year for sun position adjustment. 90% of them were seized after the first couple of years. These are conventional nuts. These were always adjusted by using hand wrenches. Gonna' have to research some alternative soon.
@@ultimatehandyman did you work as a mechanic and in construction?
Would brass or even bronze be an alternative here?
You could use them, but stainless is fine if you use a anti-seize compound etc.
Thanks for the comment
Good video, nice to know. I recently replaced the bolts and nuts on the roof rack of my truck for stainless steel since the steel ones that was on there had almost corroded away to the point of no longer being able to keep the thing together (this truck sits outside next to the ocean 24/7 and corrosion is a massive pain the ass). I wondered why they don't just do stainless steel on all the bolts of the truck, apart from cost I guess this answers my question. I'm still happy that I swapped those to stainless though, since I never have to undo/redo those bolts so seizing won't bother me so much and now, with the stainless bolts and nuts, it should basically last for the lifetime of the roof rack and/or truck.
👍
Couple questions come to mind; are stainless steel bolts more of a one time use thing? What if you slowly loosen/tighten nut every to avoid much heat from generating preventing galling?
Thanks very informative was that the rebranded Hitachi impact driver you used
The impact driver is a Kielder, I keep it in the back of the van for emergencies (its a great little impact wrench)
ruclips.net/video/2jlSqjpwZwY/видео.html
Thanks for the comment
Can you weld the zinc coated steel bolts?
You can, but you shouldn't as the fumes given off can result in galvanic poisoning. It's always best to weld non-coated metals.
@@ultimatehandyman Thank you
You are welcome ;-)
I wasn't aware of any of these issues with SS. Great video.
Thanks for the comment
Is there any negative to using a steel bolt & an SS nut, or an SS bolt with a steel nut?
I'm not sure, as it's not something I normally do.
Most of the time we use steel nuts and bolts and just apply anti-seize compound. Worst case scenario, is that you either have to cut the bolts off using a grinder/hacksaw or gas axe (depending on where it is).
Stainless and steel bolts should not gall, but there might be corrosion issues, a bit like if you put steel wool near a stainless steel sink - it can make it rust.
@@ultimatehandyman Thank you!
Interesting video, I'd never heard of stainless galling before. I've rebuilt several bicycles using stainless fasteners, and not encountered any problems like this - maybe screwing into aluminium and/or using copper grease has prevented problems.
What properties of stainless steel cause these problems?
Not sure, it could be something to do with the chromium content. Apparently if you use different grades of stainless such as a A4 bot and a A2 nut the galling problem is not as bad- or you can apply some anti-seize compound.
Thanks for the comment
Assuming the issue a user may be trying to avoid, by using Stainless Steel bolts with SS nuts, is the nut rusting to the bolt, rather than the nut or bolt rusting to whatever is being bolted; would using a non-SS steel nut on an SS bolt, or SS nut on a non-SS bolt be a non-galling solution?
I would imagine that a steel nut on a stainless bolt would be fine, especially if the bolt was coated with some copper anti-seize compound.
Thanks for the comment
@@ultimatehandyman Thank you :)
What actually happens when the nut and bolt “Gall”. Is it a chemical reaction?
John Crook That's what I want to know as well. Plus why can't stainless be melted with oxy-acet like steel can?
The oxide layer is removed and the metals fuse together.
This explains it well- www.boltdepot.com/fastener-information/materials-and-grades/thread-galling.aspx
Thanks for the comment
Ultimate Handyman Many thanks Got it.
aletoledo1 chromium ...it balls up and distorts on a molecular level
Well I for one don’t mind admitting I’d never heard of this. As you said, I thought SS was the better choice nearly always (actually, always)
Thanks for the video 👍
You are welcome
Thanks for the comment
Would a streel nut fuse to stainless bolt ?
Not that I am aware of, I have never tried it though.
Thanks for the comment
Anthony deFreitas yes it can...heat and friction are your enemy
Very good information, thanks. So does this problem occur only when using stainless steel Nyloc? The Nyloc causes much friction if you drive it too fast. I always use only hand tools or very slow rpms when fastening stainless steel Nylocs.
No, I only used Nylocks and the impact wrench to speed up the demonstration.
The washing machine rollers often gall up, and normally the bolts are tightened or undone with a ratchet spanner. I went to change a 2" steam valve a few weeks back and someone had used stainless steel nuts and bolts on that and they galled up (you can't tighten or undo them with an impact wrench as you can't get it in because of the flanges).
Thanks for the comment
What a lot of people don't know is that oxyacetlene torches work by first oxidising the workpiece and then blowing that oxide off. And stainless steel resists oxidation...
Quick question though, would you treat stainless steel bolts/screws the same as nyloc nuts (i.e. just one use) or can you replace on removal without future issues?
It depends what the threads look like when the bolts are removed. If the threads look damaged in any way I bin them and install new ones.
Thanks for the comment
Out of interest, do the same problems occur when using a stainless bolt with a steel nut and vice versa?
I don't think so, I believe it's only a problem with stainless on stainless, even using two different grades of stainless such as A4 and A2 can help reduce the problem.
Thanks for the comment
I was always taught that nylock nuts were use once only (as well as bent beam nuts - which essentially destroy the thread on tightening).
There are no set rules for Nylocks, I've never seen anything on the packaging saying "only to be used once" etc.
Thanks for the comment
If one does indeed have a galled ss bolt, what is the only/best method to remove it? If the two parts have married and became one, is it useless to even try to 'break it free' by unscrewing it?
You have no chance of undoing it, once it has galled up.
Normally I hacksaw or cut through the bolt using a grinder.
Thanks for the comment 👍
Thanks for that, I ride my bike 365 to and from work, I have gradually changed most of my bolts to stainless but there's not much stainless into stainless, most into alloy. Should be okay?
They should be fine ;-)
Thanks for the comment
Very interesting.
Another professionally produced tip top video.
Thanks for the comment ;-)
Thank you for the video. I have had problems with SS threads but I didn't know why. Now I do.
You are welcome
Thanks for the comment
great information! i believe there are grades that exist that reduce the galling and also avoiding use of power tools helps a great deal too, couple with some lubricant if possible.
Anti-seize will definitely help, also using grade A4 bolts and A2 nuts can help reduce galling.
Thanks for the comment
Thank you very much I did not know stainless steel nuts gall or that you cannot burn them off. Why is it that they push stainless bolts more than galvanised ones?
You are welcome. In some situations stainless bolts and nuts are better, galling can be eliminated in a lot of cases by using a suitable anti-seize compound.
Thanks for the comment
Ultimate Handyman If you did not know they galled and did not know that anti seize compounds are used they are not much good.
That is true ;-)
You've overlooked the lubricating done by the zinc plating. No threads are designed for repeated use of power tools, which means the bolts are not being used as intended. Perhaps they are the wrong grade of SS bolt?
The impact wrench was only used to show how quickly it can occur. On site we often come across galling, even when using spanners.
Thanks for the comment
Don't believe SS comes "graded" in different grades for a given alloy ( 304 , 316). That said, each alloy has its own strength characteristics but I don't "think" a specific SS alloy bolt or nut is available in a variety of stength grades like carbon steel bolts.
Would a plasma cutter work?
I've never used one, but I believe you can use a plasma cutter on stainless steel.
Thanks for the comment
I have noticed this problem before, if possible I try to apply a little Tallow Fat to the Stainless Bolt, also I use A4 Stainless instead of the weaker A2 grade.
One golden rule that I cannot stress enough is "KILL THE SPEED" never ever wind stainless bolts together at speed using powered ratchets, it is the speed that can cause galling.
Always wind them together slowly, it takes longer but its much safer.
Stainless does not conduct heat away like steel will, this is why you only need about a third of the power to weld the stuff, so when driving it at speed, friction heating can start off the galling.
It is Horses for courses really, sometimes only stainless will do a particular job.
When cutting, welding or grinding stainless always wear a mask to guard against harmful hexavalent chromium emissions, lest you get lung cancer.
Thanks for the comment
very very useful info, would stainless bolts into steel captive nuts do the same?
i was thinking of using ss bolts to replace some of the grotty steel ones on my classic car for the removable service stuff
what type of 'dress up ' bolts would you recommend, chromed steel?
thanks, and thanks for the great info.
Stainless bolts into steel nuts should be fine, even different grades of stainless, such as using A4 bolts with A2 nuts can help to reduce the problem. If you use a good anti-seize compound it can prevent the galling from occurring, but please be aware that stainless bolts are also not as strong as steel bolts (something to consider on vehicles).
Thanks for the comment
Mind you, if you need an anti theft bolt I will use a ss nylock
In my work I use stainless steel bolts and nuts ONLY once. Especially where there is a lot of heat involved. The only real benefit is that these do not rust, but other than that they offer absolutely no advantage at all. Once I loosen a stainless nut or bolt it gets replaced.
Thanks for the comment
Being a know all I thought the worst, at first. You taught an old dog two new tricks. Subscribed.
Thanks for the comment ;-)
what about using SS A2 bolts on cast iron?
I would not risk it to be honest. I'd just use steel bolts, preferably BZP or black phosphate coated and use some decent anti-seize compound.
Thanks for the comment
Where can I buy a pair of the same gloves you have ?
You can get them at ARCO- www.arco.co.uk/products/14A5500?s=1
Thanks for the comment
Interesting. Thanks. If a non nylock nut is used, will it still gall up? What causes the galling? Heat? Also, if the nut is tightened by hand (rather than using a drill) then will the nut come off easily in future. Many thanks.
Nylocks make the galling happen quicker as it is caused by friction. If you Google for galling there are lots of pages that explain why it happens much better than I can. It still happens if you tighten or loosen the nut by hand, I have had it happen to me several times when just using a ratchet spanner.
Thanks for the comment
Worked in the food industry for a couple decades, stainless is a way of life in the food industry. Never Seize will keep a stainless nut/bolt from seizing for a while, but does wear off if constantly taken apart and put back together. IF, you are where you don't have to have stainless but only have stainless of either a nut or bolt, a regular steel nut or bolt won't seize with stainless. Any good quality lube will also keep SS from galling for at least the first time, but when they get tight they will gall.
Thanks for the comment ;-)
So, cutting ss is a different animal. Cut off wheel (disc) works if it fits in the space, but sprays chips (future rust stains) everywhere. But using a hacksaw (or just a hacksaw blade in vise grips cutting on the "pull" stroke) works pretty well. If you happen to be cutting thin sheet metal, you pretty much have to use a fine tooth blade. But whenever the ss is thick enough, use an 18, or even 14tpi. Always use hss blades. A fine tooth blade will only polish and further work harden ss. A coarse blade is necessary bc you need to RIP THROUGH the metal. Make every stroke count. If your coarse blade is not cutting, either it is dull, or you are not being aggressive enough with it. Cheap or tubular hacksaw frames will definitely work against you here. If you are just grabbing a blade in your vise grips, wear leather gloves, clamp onto the toothed side of the blade, and cut on the pull stroke. Sometimes you can even clamp two blades together to stiffen them (clogs faster, though).
Your channel and videos are fantastic. You saw a need to present some truth, vs the epidemic of "amateur hour" videos, and filled it. Thank You
Thanks for the comment, Marty ;-)
@@ultimatehandyman I am learing many new things, your techniques are sensible.
Learned two new things by watching this video. - Thanks for sharing!
You are welcome
Thanks for the comment
So tell me something, what do the Aircraft manufacturing uses....Titanium bolts?
I think they use titanium, which I believe can also gall up!
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I'm 61. And I learned something new today.
Thanks for sharing your knowledge.
Plus, I'm a new subscriber!
Awesome! Thank you!
Not a Stainless Steel story, but along the same lines. We had aluminum "saw guides" that we had to put shims on for adjusting board sizes. We used 1/4 inch, hardened, grade 8 steel bevel head bolts that went into a tapped hole in the aluminum guide (good aircraft grade aluminum). Even with just snugging the bolts they would need a cheater pipe on the allen key, and POP loose. They were so tight that I would put a rag over the allen so it didn't launch like a bullet if it slipped out of the allen hole. Grease or anti-seize wouldn't help. Once they popped loose they would come right out with no thread damage. We had hundreds of these to do on a size change, and 95% were like that. We ended up getting all brass screws and never had a problem again. So in conclusion, for some reason those hardened bolt and the aluminum did not like each other.
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If you need to use stainless you can buy ready silver plated that avoid this galling effect (they are not the cost hike that silver plating suggests).
Otherwise I would use AG-90 Lubricant. If naked stainless is a must then try using nut at A2 grade with an A4 bolt.
Its not addressed here but the one thing that many don't appreciate is you can't just swap steel for stainless and get the same preload on the clamping surfaces for same set torque. Generally stainless gives *much* lower preload ...i.e. If you simply swap for stainless and torque up to the same then you risk whatever assembly you have just fastened falling apart (subject of course to its max design load and loading conditions.). Can be dangerous! Be careful about application.
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Thank you for this video. How did I get to the age of 71.5 years without knowing that stainless steel bolts cannot be cut by an oxyacetylene torch? Sheesh! My face is red!
Again, thank you for this video.
Subscribed.
Stainless softer then steel?
Yes, it's tensile strength is not as strong as a steel bolt, but for example when drilling stainless steel it can be harder to drill as it can work harden etc.
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@@ultimatehandyman .....both carbon-steel and stainless-steel are STEELS, just the alloying composition is different.
If you apply grease to the threads, is there any difference....?......as I apply some form of grease to every bolt or screw with my motorcycle refurbishment...
his combination on stainless, power tools and the lock nuts makes friction, the paste helps but that combo is the problem, stainless just wants to weld itself together, avoid using power tools would be the first and use plain nuts, not locknuts, then you probably wont have any issues.
Yes, using a good quality anti-seize compound can help to prevent galling.
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So how do you prevent Galling? Just put it slowly by hand? Or just not running the nut/bolt back and forth often?
Applying anti-seize compound can help. I've had bolts that have galled up when removing them with a ratchet spanner, but they have often been a machine that is heated, so that could contribute to the galling.
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Thanks for this excellent and informative video. I seem to remember that a combination of a brass nut and stainless screw is recommended for some applications.
You are welcome. I'm not sure if brass nuts would have the strength for some jobs- but at least they won't gall.
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Great presentation as always!!! 😃👍
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Ultimate Handyman Appreciate the demonstration :-)
Interesting video - never knew about SS bolts/nuts. Thanks Chez - Have a great week!
You are welcome, John ;-)
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