HSS vs Carbide | Tooling For The Mini Lathe
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- Опубликовано: 24 фев 2021
- One area of machining that can get a little overwhelming at times is tooling. For tooling nowadays there are two types that are common, high speed steel (HSS) and carbide insert tooling. Both have their place in the machinists workshop and have their own advantages and disadvantages. This is a very brief break down of the two types of tooling and their advantages and disadvantages and my experience of using them on my sieg c3 mini lathe.
I am sure that I have skimmed over some details here and there and not ever situation and material will turn the same as it turns on my lathe, but I hope the information in this video helps. I put all the information I wish I was told when I first got my lathe into this video.
Cheers 
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With 40 years in the business this is the most complete video I've ever seen on carbide in the small shop. One thing I might recommend if you haven't tried it is 5 or 10% Cobalt cutting tools . I highly recommended them. Slightly more expensive than high-speed but hold their edge three to four times longer.
P.S. I just subscribed.
I can say the same. The Hss Cobalt are the way to go. Even stainless is easy to work on
I'll never use the info in the video but I'm very happy i watched it - you rock thumbs up
I've found that brazed carbide lathe tooling is the best of both worlds. It is important to buy name brand brazed carbide and avoid the Chinese mystery tooling. The name brand stuff is inexpensive and with a 6" silicon carbide grinding wheel for $20 you are good to go. There are 3 grades of carbide tooling. One is for iron and the other is for everything else. The third is good for everything but is a little more expensive by a few pennies. I have brazed carbide lathe tools that are 40 years old and still have plenty of life in them.
You can grind your tooling as needed just like high speed steel and when it's chipped or damaged a few moments with your green silicon carbide wheel has you back in business.
In a commercial business insert tooling rules. Time is money and you can't waste time sharpening tooling by hand. Just as important changing a damaged or worn out insert with a new one often means the tool setting is very close to the insert just removed.
Cheers from NC/USA
In my experience there are multiple grades of carbide for specific materials.
When I worked as a turner it was specific for cast iron with a different grade for the stain less steel shafts we made (way beck when, all brazed carbide) Insert tooling was a rarity in the 1970's even in medium sized machine shops.
I agree, for general model making use brazed carbide are hard to beat as long as you can grind/sharpen them I picked up a RJH Ferret diamond honing machine and its great for brazed lathe tools.
well it's a lathe ruclips.net/user/postUgkxN9zrzkkhnjUF5PQbuA_B1gYdsfCu9k6z but it wasn't what i would have anticipated. Headstock, tailstock, carriage apron are manufactured from aluminum now not cast iron. The spindle diameter for the bearings is too small allowing for a few play in the spindle so I am using some blue Loctite to take out the play.
One difference between HSS and carbide most hobbyist and myself didn’t know about was the (work stress) a lathe or milling machine can endure without excessive body twist and therefore chattering.
HSS cutting edge can be grind very sharp to reduce work stress in small / hobby lathe perhaps fitted with an upgraded motor.
On the other hand carbide cannot grid to equal sharpness without risk of chipping off at its cutting edge. To avoid chipping, carbide were manufactured with a designed radius (dull wo/apex) at its edge.
Caveat? Carbide cutting edge will glide / skid on the work surface at a load normally applied with HSS, unless we deliberately force / dig it into the material. That cause a small / hobby machine chattering.
Chattering? Can be improved with rigidity in the system beginning from removing free play at sliding junctions. This causes assembly difficult to slide. Remedy? Reduce profile ripple on sliding surfaces. How? By counterfeit scraping referencing to a flat certified granite block.
If chatter persist? Admit we are a creative hobbyists with a flimsy machine. Use HSS with coolant, reduce feed rate, reduce advance rate between each pass, change spindle rpm and continue creative.
What’s a problem to use sharp-ground inserts?
@@romanplutok6202 problem is that - carbide edge modified form radius into a very sharper edge - the sharp edge will chip unless the feed depth and rate are significantly reduced.
@@philoso377 That’s not really correct - carbide edges are very different depending on application - edge roundness may vary at least between 15 and 75 microns depending on application. I guess you don’t think that turning of aluminum, plastics, composites in industry is performed with hss tools, right?
Just select the right insert
Contrarily, I prefer to turn plastic, aluminum, composite with HSS. We can use whatever tool toughness / hardness we want as long as we apply the correct edge radius, feed rate / coolant, depth and surface speed, provided edge is harder than the load.
@@philoso377 I guess you prefer to use HSS because you don't have proper carbide insert and don't have production volume which would make sense fro you to get ones
Sure, you can what is more convenient for you - can even use tool steel for some these materials :)
The thing is that's wrong perception in general that "HSS is sharper" - I guess it came from hobby-class workshops where machinist usually not so picky about inserts and also don't have the knowledge how to select them and what the third letter in ISO insert code stands for
But I can tell you that no real serial production runs hss turning tools and you can select insert sharp enough to cut down to ap 0.1 mm with fn 0.02 mm/rev - and in 99.999% you don't need to go below that ;)
Just getting into machining with a little lathe I picked up and this was very helpful. Looks like I need to grab some HSS
GREAT summary video! I couldn’t agree more with everything you said as I’ve discovered using both types. 👍 I would have added that with carbide you need to nearly double your rpm & feed rates, as well as it not requiring coolant which is a huge benefit on the cleanup perspective not having to clean up spun cutting oil everywhere. Also would have been worth mentioning about the different carbide coatings which mate to steel vs aluminum.
I have 8mm HSS blanks that have been used & reground for 20 years... 😏
I'm not a big fan of carbide unless I'm machining something unusual... particularly when running a small lathe, you can grind a fairly aggressive rake which will DRAMATICALLY reduce the horsepower required to make the cut... 😎👍☘🍺
This was a great video, thanks!
I don't think I can manage a grinder in my apartment so I was wondering what to best equip my mill with.
I think I'll stick to carbide for aluminum but after hearing about HSS being sharper, I think I will use that on my plastics.
Because my small lathes are cnc and used for production, I use carbide inserts. AK style inserts for aluminum are not the only inserts that have the really sharp ground edge. I use the Sumitomo FC style inserts which has the ground edge but a rake of 15° which makes the edge a little stronger. There must be other inserts around that are similar, these are called "Finishing" inserts, so intended for light cuts, which are probably still pretty huge by are our mini lathe standards. I would suggest that metal removal can be much the same, as the spindle can be run flat out with carbide, for most of my work the maximum of 3000rpm is theoretically too slow. As a guide anything non ferrous below 30ø can be run at 3000rpm and for steel at 100m/min surface speed (which fairly conservative and a low figure) anything below 10.5ø can be run at 3000rpm.
I must admit though that in my larger manual lathe, I do like moulded inserts. They deal better with any operator that is a bit clumsy and bangs the tool into the work, not me of course! LOL
My first set of tools for my 1930's mini lathe cost me about £5 off of Aliexpress, brazed carbides and as long as I don't sweat them too much produce a very nice finish, better on softer metals but slowly handles steels with care. Got a sweet set of spot drills off there too for couple pounds, an angle protractor for about 80p and a very nice quick change tool post set for £20 coming with 5 tool holders incl a boring bar holder and a parting blade holder but they skimped on the grub screws so changed them for longer high tension allan bolts on the standard tool holders as the brazed carbide's are quite small, ideal for a mini lathe. I haven't fitted the tool post as yet because to do so, I have to pull a stud from my crossslide or make a sleeve nut to fit the existing stud. Next job is to try and find or build a transmission axle, I have en route a jack shaft with suitable 3 step pulley, waiting on finding a suitable tall mount to mount the pillow bearings to hold the jackshaft which will give me three speeds from my motor. I have watched most of your videos and learned so much too.
Thx for posting my guy...👍
Thanks for the information.
Stefan Gotteswinter showed on his channel that while mass produced carbide is not as sharp as HSS, you can grind it to be just as sharp. Just use diamond abrasives and don't breath the dust.
Sharpness also isnt the only consideration, durability is arguably just as important which is what can make sharpening carbide worth the extra effort :)
I use hand ground and wire edm made carbide tools on my lathe.. biggest advantage I'm able to make my own tool geometry, and mostly use them In titanium..i buy carbide rods of ø4mm or use broken or dull endmills to make my lathe tools.
or just buy sharp inserts if you need sharp ones 🤷♂️
Yep, they are dulled on purpose during production.
There are a few reasons for this, mostly durability and surface finish. A razor sharp edge is very fine and has a tendency to dig into the work.
One major advantage of coated carbide I've found is machining aluminium.
There is far less edge build up compared to HSS. Saying that, I still mostly use HSS on 6061 but it does need lubricant ( usually mineral spirit) which can sometimes be messy. I have also used cheap synthetic motor oil thinned down which works very well (diesel also works well and isn't too smelly)
Isopropanol is a superb cutting fluid with aluminum and probably other non-ferrous material, but being alcohol it takes some care not to prevent rust.
Great info. Thank you......
More spindle rpms and no need for coolant are couple advantages that carbide inserts have against HSS, but yes HSS has its place. I prefer carbide inserts.
Great video !
Nice video for folks starting out. You can use the sharper AK geometry in carbides. eg. CCGT060204 AK H01
Cheers. I have used these sharper insets before but for the mini lathe, my experience was mixed. They do perform better than the ones I used in the video, but the edges were very brittle and the lathe was not rigid enough to prevent them from breaking when I took moderate cuts. I still found that the HSS was sharper and must more resilient. However I seen some people use them and get good cuts on their mini lathes, maybe the ones I purchased were duds.
Good video with helpfull information, underrated in views tbh...
Great informative vedio,,Thanks
Good information.
Glad it was helpful! Cheers
Great video, full of good information.
There are a couple of improvements I'd suggest for your mini lathe, that will further improve accuracy and surface finish.
First and foremost: That tool post. I had one just like it... It's a quick change, your tools are "always" on center, and the price point makes it VERY tempting... But after using it a few times, I can honestly say that those cheap aluminum tool posts are absolute garbage. First, they're aluminum, so your rigidity is handicapped right out of the gate. Further, the tolerances on the dovetails are terrible, so repeatability in X, Y, and Z is utter trash. And again, rigidity suffers greatly. Do your lathe a huge favor and upgrade to an Aloris-style 0XA wedge-type tool post. They're a bit more expensive, but the Chinese clones are actually pretty damn good, and the increase in rigidity and repeatability are MORE than worth it. I can't recommend this enough... It's probably the single best improvement I've made to my mini lathe. Deeper depth of cut, and improved surface finishes are a tangible result.
Second: Inserts. Inserts meant for aluminum are where it's at for these small lathes, even in steel. They're much sharper, and have a positive rake angle. This reduces tool pressure considerably, which helps a great deal with the inherent lack of rigidity these little lathes have.
Another easy thing that can improve rigidity is adding locking screws to the compound and cross slide. Simply drill and tap a hole for an M4x0.7 socket head cap screw between the first two gib set-screws of each slide. Tightening the screw locks the gib against the dovetail, and you'd be surprised with the difference this can make with rigidity.
Optionally, getting rid of the compound completely, in favor of a solid tool post block, is also a great way to improve rigidity, though this requires some effort and tooling to make. Again, though... It's well worth it for the deeper depth of cut, and better surface finish.
Keep up the good work. These lathes get a bad rep, but they can be capable little machines, if you put in the work. Great to find someone else making good parts, and good content, with a mini lathe. Cheers!
@@davidwillard7334 Not sure what baloney you're talking about... The video presents good information, and demonstrates that good parts can be made with the equipment shown. I made some suggestions for further improvements.
@@davidwillard7334 TRY!! TAKING!! YOUR!! HEAD!! OUT!! OF!! YOUR!! AZZ!! AND!! STICK!! IN!! YOUR!! TYPING!! FINGUH!! INSTED!!
RUclips seems to have an opinion on what you can cut on one of these mini lathes.
I got an ad for cheese.
Maybe it was the cheese you used for your demo.
Thanks mate. Just what I needed. Where in Sydney is a good place to buy?
just try CARBIDE TURNING INSERT,ALUMINUM with ebonite pen blank and it work pretty well when we turn nylon, acetal.
i mostly use inserts made for cutting aluminum. those are sharp as and you can also cut steel with em, and the resulting finish is excellent.
Glad to hear that you like the aluminium inserts. They are certainly a great option. I have used them but on my lathe I just couldn't get them to work. The edges were just too brittle for my liking. Cheers.
Excellent video. Many thanks!
But what is that holder at 7:32 ? The patterns are intriguing.
Brazed carbide is fine as well. The cheap ones needs to just lap on under 10 times on a stone and good to go a long way. From China brand new its dull out of the box.
Popped up again in suggested, so I am here again. I really wonder where this video would have gone if the cracker fitted in the toolpost. I was going to say that brazed carbide inserts don't deserve there own video but I see that right at the end of this comment is your thumbnail for exactly that. When I was an apprentice back in 1964, they were what we had, now really not worth bothering with, just not sharp enough for use with small lathes.
very good
I believe the trick with carbide inserts in a small machine is to use the type of insert called a finishing sharp. Unlike standard tooling, made for deep fast cuts, finishing sharps are optimised for lighter work.
I've tried these in the past, and whilst they do cut better than the regular dcmt ones I use, I've found that you need a really rigid lathe to get them to work, or the edges can easily break. Cheers
I have a green wheel on my grinder, which means I can sharpen or reshape TC tip tools.
I agree, china seems to produce decent enought carbide, hope it will continue and they don't mess it up like they do with HSS.
Wanna know the reason thair carbid is good? Its B/C the olny thang that will cut Tungsten carbide is Dimond.. soo in return the grind on the tool is much much better more precise goid smooth finish ect.. its not because they give a shit an lut extra care into it lol its just a side affect of the dimond grind.. ;) your welcome
You can also purchase high speed steel inserts.
I am aware of that, however I have yet to see a local vendor sell them, if I see them I will be sure to pick up a set because I'm very interested in seeing how they perform.
Mate where do you buy yours they seem cheap? Please let me know. I’m just starting out. Thanks.
If you don't learn grind lathe bits you will have problems turning materials that require special tool angle. Plexagls comes to mind. any toll that cuts or drills need a zero rake so it doesn't fig int to the plastic. ull nosed forming tools, tools that leave a radius and more are beyond you. I started using a lathe in 1959 for a science project. Later, I ran a lathe for Brantley Backoes and then Vrantly-Hynes Helicopter. I bought a Chinese Mini Lathe about 20 years ago. Even as bad as my eighty year old eyes are I can still freehand grind lathe bits. I have tool steel, brazed, and Inserted carbide tools. I almost always use tool steel bits if I need to turn something too hard for tool steel to cut, and I am in a hurry to take it to a bigger lathe. A Mini Lathe can barely cut hardened 4130 that a full-sized lathe rolls a dark blue 500 F chip off of all day long.
For those of you wondering HOW the TITANIUM NITRIDE coating is applied to something like a CARBIDE tool ... It's actually quite impressively done molecule by molecule via process called physical vapor deposition (PVD). It's put in a chamber and I believe they give the target an electrical charge while heating the substrate up to transfer it ... If I recall, there's a channel called AlphaPhoenix which demonstrated the process as they guy is an actual physicist who works in a lab in which PVD is applied (along with other projects that I think include some fundamental physics experiments).
You forget about HSS inserts
I get absolutely TERRIBLE finish cutting aluminum using carbide.
No idea why.
Cutting at any speed or depth makes little to no difference.
oh my that cheese looks deliciouss..... can't finish the video now, i'm off to buy cheese.
steel vs. ceramic, steel is toast
God bless.
Can i use hss to machine chromoly?
Yes
Those coated DCMT inserts are absolutely the wrong tool for turning plastic. As you stated, they are pressed and sintered and are so are not NEARLY sharp enough for cutting plastic - it just makes a ton of heat and poor quality finish. The coating makes them even duller. You can purchase manufactured DC inserts with a "honed" edge, which are ground from the factory with a ground edge on them, but by far the best tools for this sort of work are just uncoated carbide insert blanks such as those made by Applitec or brazed carbide with a bit of extra sharpening.
Carbide is a pressure cutter, HHS/Cobalt can be sharpened to cut with little pressure, should be all you need to know if you are using low powered equipment
Just get positive rake inserts. Literally the exact same geometry with a stronger cutting edge for higher sfm.
This comes at the expense of higher edge chipping.
You gave only part of the carbide information the last number of the 3 digit number that follows the letters is the tool nose radius 1= 1/64...2=1/32.....3=3/64 your triangle inserts are 2 and a 1 will give a much finer finish . You compared a 1 radius HSS to a 2 radius carbide. Go back and test the radius against the same radius. you might be surprised. And L think you'll find that the other 2 numbers have meaning also like the size and the coating of the insert.
What tool shape(s) are you using ALL THE DAMNED TIME! Consider tool holders and inserts for those. Otherwise, your likely better served by full carbide or HHS.
If you NEVER use cutting (cooling) fluid. Inserts might be worth the brittleness. Dry or FLOOD, there is no drip!
Carbide rubs high speed cuts .. simple as that
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Mini lathe are not really enough ridge for carbide. A good hss tool is great.
No mention of coolant????????????????
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cheap Tool holders from china and carbide plates cost almost nothing, you dont need the HSS to regrind etc just change the plate
Do you know about crobalt or stellite or blackalloy? These are all based on 50% Cobalt and 30% Chrome. The punishment they can take far exceeds M35 or carbide.ruclips.net/video/iAPyWKXnVFM/видео.html. And when you use it in combination with the diamond tool holder this guy promotes you only have to sharpen the end of the blank. Not three sides like a normal cutting tool. These tools are sharp like high speed Steel but they hold an edge for much longer. It can also be used at higher speeds.
So summing up, carbide is the way to go. Let's skip the bullshit dance 💃. Get right to the point😮
First! 😂