The #1 thing DIY dudes don't understand about torque wrenches | Auto Expert John Cadogan
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- Опубликовано: 11 окт 2024
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The correct torque setting for every fastener is “hear nut crack, quarter turn back”
@@timh6845 FT
Hates Ev’s cause they ‘burn’ but is sponsored by Bluetti! Hmmm, if an ev company sponsored you, you’d be all over them.
I needed the maths…ruclips.net/video/0f746pF1xc0/видео.html
@@Super--Star What's so laughble is there's tonnes more ICE vehicle fires than EV's, lol. And it's not just because there's more ICE vehicles.
I know I’m getting old because I just watched a 20min video about torque wrenches and loved every minute of it 😂
Ditto!
I prefer to use the term "mature". Or perhaps "vintage".
I hope you ignored what he said about where you place your hand. Lol as it makes no difference to the settings at all.
If only there was a way to prove this.
@@CleverMonkey-jd3du for those of us that know simple leverage and stuff like that child's play really. We don't need to explain it other than may be to some that are a bit backward in the field. But if I was this guy I would remove the video. Thank god for few that believe what he has said none of it can harm you. But what else's has he posted that might cause harm. I think RUclips need to do better vetting as I said if it was a book it would not of got published.
I just so happen to have a torque wrench calibration tool and a clicker style torque wrench. I didn’t think it made a difference where exactly you held the handle either so I was like I have to try this! Here are my results. I alternated back and forth between grasping the handle and at the half way point. Performed each 3 times. Torque wrench set to 50 ft lbs.
grasping handle- 52.3, 52.6, 50.6 Grasping half way- 58.5, 58.3, 56.9
Torque wrench set to 75ft. lbs
Grasping at handle- 76, 75.3, 75.3 Grasping half way- 87.3, 87.2, 83.2
Torque wrench set to 100 ft. Lbs. Grasping at handle- 100.2, 99.3, 100 Grasping half way- 113.7, 111.6, 112.6
It Does make a difference!
Sometimes you just gotta get empirical. 👍
damn honestly i thought at first its bullshitium but holy if these are actual numbers you got then it makes total sense to not half grab it
Thanks for that now my brain hurts
Did you keep maintain the same angle of nut and socket? Think about stacking 10 adapters between nut and socket. I'm sure you made the same mistakes as on the video
How can it be mechanicly if the handle ar the same one peace...?
Don’t talk to me about wrenches. They drive me nuts.
Then you're screwed...
I'm face-palming and groaning. I'm also jealous that I didn't think of it first.
Don't talk to me about wenches
My (hex) head is spinning.
Great thread to study ….
I vote for:
1. Calibrate video
2. Comparison to other torque wrench types
3. Digital Torque adapters
4. High End Digital Torque wrench with lights and sounds.
Allen Millyard is an engineer who makes some unusual motorcycles. ruclips.net/video/PHOUEhLZ-MA/видео.html shows him checking the calibration of a torque wrench.
I second the motion!
This guy does a calibration video from 7yrs ago ruclips.net/video/RsMxtEx0uik/видео.html, and look up "Project Farm" on youtube, compared like 15 different torque wrenches
@@CaptainRon1913 yeah we know about google.
Don't forget to store the wrench with the tension spring in a relaxed state and when you use it do a few gentle clicks at a low setting to test its working correctly.
also dont use it as a breaker bar to undo bolts beyond its max setting.
We have torque wrenches that do not need to be unwinded. Times change.
You shouldn't be using it as a breaker bar, or using it to undo/break the fastener loose, no matter what the setting is🤣
However, you can use it as a standard ratchet to tighten the bolt to torque, or remove the fastener out once it has been broken loose etc.👍
@@mpspuijdepends on the wrench. Most spring type do require backing off. Deflecting beam for example, do not
Springs don't work differently in torque wrenches compared to everything else. It just isn't physically possible. The assertion that you need to relax the spring or it will wear out is ignorant. Properly made springs only stress when changing shape. This is a fundamental reality of springs. You can leave them at whatever tension you want, they will be fine. By lowering the "tension" after every use you are in fact wearing out your spring twice as quickly.
Which is why you can leave magazines fully loaded for decades without issue.
How do you account for the thousands of fixed-torque wrenches that sit for years at the same setting? Cycling the spring does more damage than leaving it alone.
If you buy a W&B deflecting bar torque wrench or inherit your late grandpa's W&B wrench ( mine will probably be sold on ebay when I buy the farm) do not use it to undo fasteners or you will destroy the calibration. Only for righty tighty use. From my experience tyre stores and other automotive service providers are yet to hear of its invention. I think John will get this!
40 years ago as an apprentice motor mechanic we visited the W&B factory and were told in no uncertain terms that using a deflection beam torque wrench to undo fasteners WILL NOT do any harm to the calibration. Can't get more emphatic than that, having said that, 40 years later I still don't use any of my 4 W&B torque wrenches to undo anything.
Back in the eighties when i did an appreticeship with repco as a reconditioner they used and sold warren and brown stuff and they sold kits for repairing the torque wrenches. One day we had a monster torque wrench show up from the mines to be repaired the shaft had been bent in half from memory this unit would of been 5 to 6 feet long close to 2 metres for the young ones. Apparently the mechanics were using it to tension up wheel nuts on a loader so they stick the wrench on the nut and then move the machine to tension them. this one was way over tensioned . On another note one of the jobs while at tafe was to make a torque wrench which was an exact copy of a warren and brown the only bits we didnt make were the little spring inside the click mechanism and the square bar the socket clicks onto. I still have and use it today it is over 40 years old.
Always remember to zero a torque wrench after use, then put in box. As a cycle mechanic my torque requirements range from a low as 1.5 Nm, to 55 Nm. My rule of thumb is to aim to use a torque wrench with the target torque towards the middle of the wrench range. Basically I prefer not to use a torque wrench at extremes of range. Great vid.
Split beam torque wrenches don't need to be stored at zero fyi
Warren and Brown deflecting beam has been my trusty friend for a couple of decades (a birthday present from SWMBO - she twigged early in our relationship what makes me happy :) ).
No temptation to grab it in the wrong spot with a deflecting beam model ;)
Agreed - that type is next-level. W&B is awesome, too.
I have a w&b deflection too. It's nice to use but not fast.
A deflecting beam wrench requires that you keep the handle centered on the pivot. Also, it's nearly impossible to use a D/B in tight spots, or when you're crawling around under the car.
Thanks for the video JC, when I was a spanner spinner in the Navy working on helicopters, we had a large ‘Clock’ style torque indicator. We never trusted the markings on the wrench to set the torque.
It was great because if you had to use a extension you could accurately set the tool.
Of course there were all of the formulas available as well if you wanted to do it the longer way.
Now that I have retired and started tinkering with the car & motorbike at home, the only tools that I have that get the ‘Kidd Glove’ treatment are my torque wrenches, digital & traditional vernier & glass inspection mirrors!
Regards,
Shane.
A quick PS - lots of people don't understand that a complete moving sweep to the click off point is essential ie you tighten up to say 5 lb short of the click off point and run out of swinging room, you need to loosen off because there might be say 10 lb to overcome the "bite" in the fastener.
I've noticed that most fasteners that are specified to be torqued in stages, the last stage is much larger for this reason.
@@5000rgb Yes had noticed that and it generally gives you a shortish sweep on the last stage which makes sense.
Made a deflecting beam type when undertaking my Apprenticeship in 1985. Still works a treat 😊😊
Yes I still remember making one of them in the 80s - perfect copy of a W&B - very good exercise in machining / milling and shaping.
so did I back in '72, also have a couple of Warren and Browns
I have a.3/8"and 1/2" W&B deflecting beam torque wrenches.
Invented by Walter Chrysler late twenties.
Recently checked calibration and still spot on.
And yes it crucial where you hold it on the handle, it will have a profound inaccuracy if choked.
The spring type you demonstrated doesn't matter a rats arse where you hold it, you are only overcoming the spring tension.
I agree - A deflecting beam is an entirely different device to a wrench with a fixed force threshold detecting mechanism.
Absolutely, have a look at this guy’s garage. He doesn’t use any of it anymore if ever. It’s not even a workshop any more, just a set for his RUclips channel.
Yep a bit of a Fraudster, his No 2 Thor copper/hide hammer in the foreground is unmarked, can see now why he had 5 wife's
It very much does matter even with the tube type he is using, the pivot point for the clicker is about an inch or more down from the socket head at the pin meaning they experience a different amount of force when the same pressure is applied on the handle.
This discrepancy however is accounted for if your hand is in the correct position, but if you choke up on the handle then the ratio of force between the socket head and pivot point changes.
Moving your hand halfway up the handle will for put your hand 50% closer to the socket head meaning you'll need for example 50% more force to apply the correct torque which if fine, but since the pivot point for the clicker is an inch or more down from the head it'll be about 65% closer to your hand instead meaning it will take more like 65% more effort to make click at the same torque setting meaning you're overdoing it by about 15%.
If the pivot point for the "clicker" was at the socket head than this wouldn't be an issue which is the case for many wrenches like the newer electronic ones
Mentioned in other comments I already see, but this is one of the reasons I have always preferred deflecting beam torque wrenches. They're almost impossible to use wrong. Mine are W&B as well, and they have never let me down once, even on bolts I stake my life on on my motorcycles.
W&B defecting bar torque wrenches are crap and better for amatures to think they're good.
They are actually easy to mess up with, if you forget to press the pin in you can ruin a torque sequence, which I have done.
I have a snap-on deflecting beam that auto resets it still clicks perfect.
I also use my snap-on digitals too.
@@shanerorko8076I take it you are a snap on fan boy then.
It isn’t hard to remember to click with the W&B.
@@tomnewham1269 No actually I'm not, yes some of my tools are snap-on but the majority aren't. All three of my torque wrenches are snap-on as the ratchets are better, infact nearly all my ratchets are snap-on. I have no issue with their torque wrenches plus I get a better ratchet head like on my 3/8 digital which is 72 tooth.
Snap on micrometer adjust torque wrenches are made by CDI, and I must say the W&B torque wrenches of the same design appear to be the same tool.
Same concern applies to beam style. Grab off center of handle, wrong torque applied.
You're bending a calibrated beam. Amount of beam being bent matters hugely.
The first torque wrench I had was one that worked by bending a steel bar. The handle was on a pivot that assured that the applied force was at the right point.
Useful video JC. Years ago my uni applied mechanics/strength of materials lecturer (a bit of a car nut like most of us part time students at the time) said - " do not damage your nuts, spend your $ on a Warren and Brown deflecting dual signal beam torque wrench. Your nuts will always be in good condition"
I figured out how to recalibrate my torque wrench using exactly the item you mentioned. I remembered the law of moments I learnt in physics classes 52 years ago. Glad to have my procedure confirmed by someone with the knowledge. ❤
I was told that it’s also very important to set the torque wrench to zero every time you finish using it or the spring inside compresses over time which also destroys the calibration
Mech engineer here. Highly unlikely to significantly effect spring steel unless stored for yeeeears.
If you must, roll back to a lower torque setting but never zero.
@@Itsmellsfishy I went with an electronic torque wrench out of sheer laziness and getting misty eyed over all the features like how it can remember the angle you had it if you run out of room and have to ratchet back. Brilliant for torquing head bolts with no foresight while the engine is still in the car
@@danieljones7843 I look forward to finding a way to write one of those off one day lol
This is a good video, and thank you. I had to take a small course on torque wrench use in the military for working on aircraft; to be certified to use a torque wrench and evaluated by an QA inspector to make sure I knew how to use it in a variety of ways, including the use of open end crows feet and angled extension adapters.
This indeed matters for whisker and spring pin style wrenches like a WB. They measure the deflection of the handle and that needs to repeatably loaded from a set position. Choke up on them and it alters the total deflection and to achieve accuracy that distance is measured
However in a 1/2 decent wrench say like a Norbar hand position doesn't matter. Why? Well the spring loaded break away and pivot never changes relationship and other than torque adjustment it is always the same. The speed applied will alter the breakaway point torque as friction always plays a role. It may vary slightly only due to the deflection of the outer tube but isn't usually a factor in a well maintained unit.So grab the handle anywhere on the outer shieth and it repeats. The thing that changes is the input torque required but the output remains consistent.
You have lost the plot with this one.
WB u have to use the handle no where else
Well said,I agree
@@margarita8442 You have to met the mate of mine who two handed gripped the whole thing (fingers around both bars) and wrenched on it. I have not loaned him a tool since....
An eye opener. Thank you. I am still wary after, 50 years of working on cars, of using torque wrenches. This is simply because About 50 years ago, I removed the cylinder head on my first car. It had a Ford 1172 side valve engine. I borrowed a barrel torque wrench to do up the head bolts and broke one, because no one had told me how to use the wrench. My efforts to remove the broken thread were useless. Now, thanks to you, I know not only how to properly use one but also how it works. Brilliant.
Yes please, a video on torque wrench calibration. Third party calibration will cost me more than what I paid for mine.
Two things, when I did my apprenticeship in the Uk in the early sixties we were trained on Brtitool and we were taught to always relax the inner spring when we had finished and not leave the spring under load, secondly, when I was in Australia in sixty-eight I bought a Warren and Brown Dual Signal torque wrench, I'm now seventy-eight living in Ireland and I'm still using it.
A metallurgist will take issue with that theory,as his training and theoretical experience tells him that the type of metal a heat treated spring is made from does not suffer from deformation when under a constant load below the metals yield point.
The metal changes its mechanical property when subjected to cyclic loads.
So,in reality,the spring is more likely to deviate from its designed value if you were to constantly change the preload on the spring.
When you first started talking, as someone who had little idea how torque wrenches work i thought theres no way that moving your hand makes it wrong, but decided to stay quiet and listen to the video, boy im glad i did, very well explained!
I had a cheap torque wrench like those you have there ,it went out of calibration so I threw it out and bought a new warren and brown deflecting beam torque wrench .Made in Australia 🇦🇺. It will last a lifetime
I got a Wawen & Bowen and thought I was a Warren & Brown, but later found out it was a Chinese made product. I should have known from the spelling. Guess they spelt it the way they pronoun it.
@@lozza2272
😂
That's funny
Great video, I've sent this to my son. He is doing his first year school based apprenticeship as a diesel mechanic (2 days work, 3 days school).
@13:43 "It doesn't know that you've changed hand position". Isn't that the point? It's a rigid device, you might have a hold on it closer to the fulcrum and therefore have to put more muscle into it, but your effort(force) at the grip point will equate to less force at the 'handle' where the knurling is and it will be as though you were holding it there. Because it is a rigid lever. Same if you shove a pipe on it, it's still a rigid lever a d as you said "It doesn't know". Just imagine if you set the torque to your favourite setting because reasons, then welded the adustment in place so the whole tube part really is a rigid lever but the "click" point never changes. Does it really matter how or where you apply force? I dont think so.
I'm exactly on the same thought train as you, I'm confused how mechanism within the rigid body would care where you hold that rigid body, all you do is adjusting effort needed on your side.
Same here, he never stated that the outer tube deflects, mearly that the ramps slide across each other.
Ill be disappointed if a digital torque meter that only registers the initial torque peak upon click isn't used in next video.
My bet is there'll be essentially no difference in torque.
Will be an interesting watch regardless.
I'm replying to myself here, I'm starting to believe everyone is right, up to a point anyway. If you set the thing to a value far beyond the required torque, then it is like a breaker bar, and hand posjtion is completely irrelevant,. However, if it is set to a required value, then initially it's a rigid bar and hand position doesn't matter, but as you get close to the 'click' things begin to move inside, the spring begins to yeild, the ramp begins to slip, and the pivot pin begins to be relevant in relation to the cntre of the bolt. Then it matters. Is that getting close to what John is saying?
It's not a rigid device, it moves, how else would it click,you clickhead
I have a beautiful Warren and Brown torque wrench. It is a deflection beam style. It was passed down to me by my grandfather. I'm an automotive mechanic. And blessed to have it. This wrench has assembled thousands of engines. I have it tested and certified every 12 months. And in the 30 years that it has been in professional use. It failed Once!. One phone call to the manufacturer had a overhaul kit . A small bag of a spring, a pin and small parts kit. That was done 12 years ago. My torque wrench is kept in the same aluminium box that my engineer grandfather and I made when I was a small boy. . The can't be said of the similar """crap ""on"" wrench that has done less than one years service. And has cost a weeks wages.
Nar John. The outer tube moves independent of the internal ratchet handle section and doesn't care where your hand is. So swinging on the outer tube closer to the ratchet head would require more force to achieve the same torque, but it will still result in the same torque. Likewise, if you chuck a pipe on the end. The outer tube will still move about the ratchet handle, but you'll be able to apply less force.
Looking forward to getting dragged out in your rebuttal video tomorrow.
Cheers
PS enjoy the username I made when I was 15.
Go back in time and tell baby you to pay more attention in school.
@AutoExpertJC good advice for most people, but my response shouldn't be the trigger for it.
FFS genius: moving your hand = samentorque for the click; different torque for the fastener. Time machine for you.
I thought the same as @big1000al, so I had to reseach why and changed my mind.
On a normal wrench, T=F*R, where R is the distance from the axis of rotation (the bolt)
But on a click style wrench, it's a double pivot mechanism. The axis of rotation, and R of the force you apply is the click pivot. Not the bolt.
That's true, Two fulcrums; same effort. Different torques.
I was glad to see how these are constructed.I used to think it was activated by a ball bearing at the end of a strong spring running the full way up the tube, with the ball bearing clicking in indentations on a wheel about 25 mm in diameter, which would be utterly ridiculous.
As an aircraft maintenance technician/quality control inspector, this is extremely important information to know. Thank you for explaining this in a relatable manner. This should be mandatory training for any maintenance technician.
No offence meant, but shouldn't you already have known that in your profession?
@@io3204 I know these things, but most new guys are only taught the basics of how to use torque wrench. Things like not choking the handle aren't discussed much. The internal workings and overall physics aren't taught either. Those can help people understand the process.
If you’re an aircraft maintenance technician and believe this crap, please don’t touch planes! If it was so important you would’ve even taught it at trade school.
i do enjoy your explanations. as someone who only lasted at school till i was 14 and rarely attended, i did miss out on a lot. luckily i have always enjoyed learning since then.
You can, however, calibrate the wrench you're going to have to choke up on with another wrench if its a crucial situation... you can do it with the hawksfoot as well. Run the control wrench to the correct torque+1 then back the one you'll use off until it clicks first with the hand position you'll need to use.
However in such a situation I'd advise a piece of rope on the wrench handle with a stirrup! Learned that from an ASE Goonwrench with a bad back! Works over car bonnets, off axles, under and over cars and even on a belt hook.
Knew a guy who complained about classic torsion wrench handles being wiggly.
Nice explanation of how torque wrenches work. Especially the disassembly. And YES I would like to see you calibrate a torque wrench (TW).
I bought a cheap TW from Aldi of all places only to find the screw thread in the grip was shit and would not turn smoothly. My mate has given me a better quality TW which I will use. But I would like to disassemble the Aldi TW to see if I can smooth the thread and make it usable. One issue is that the thread has a square profile and I don't think tap and die with that profile is cheaply obtainable. I will definitely NOT mess with the set screw setting. Calibration demo, yes please.
It's not that difficult to adjust it. You need a known weight a ruler and that's it.
This solves the years old, mysterious valve cover bolt that I broke the head off of. Thank you! I must’ve been choking up on the wrench. It all makes sense now.
A very good breakdown of the construction and I accept that every point you make is valid, but what confuses me is the, unlike a flexible tension wrench with all the readings on a big plate near the handle, the operative word being a flexible piece of steel which relies on its flex for accuracy, but on your type, the tubing has no flex part to play so where one places their hand either on the grip or a few incheds up, would not seem to affect the calibration you have put in by twisting the adjustment?
Unfortunately old mate wasn't really able to explain what actually facilitates this torque difference in 20 minutes, but there is a logical reason for it:
When you pull on the tube, some of your pull force gets transferred through the pivot point and directly to the fastener, instead of going through the torque spring. If you choke the handle, more force is being applied through the pivot pin and not to the spring/clutch; pull further away from the handle, less. This is because you are applying increasing axial load to the pivot pin as force gets applied to it closer, and less to the opposite pivot point (the roller clutch). The torque wrench is calibrated to account for a certain amount of torque force transfer through the tube pivot.
In any case, in practice it's pretty far from being the ' number 1 ' inaccuracy in torque wrench usage. Pulling too fast, ratcheting too close to set torque or applying axial loads to the fastener / wrench body (like having long extensions, loose sockets or angling the torque wrench vertically), as well as other things like thread friction and component settling are much more common things that are all very pertinent for DIYers to be aware of.,
@@ybliga na any major slop in the wrench would likely spin your calibration out in a different way, there's some much better videos out there where people go and actually use their torque wrenches to demonstrate this effect, rather than just talking tangents about it. Here's one like that: ruclips.net/video/RsMxtEx0uik/видео.html
To be honest, given the speed with which the latest video was posted it kind of seems John was banking on people disputing the basic explanation given to spin a bunch more videos out of it. Well... I DO understand the need for a content-creators to make popular content, and making fun of people under the guise of education is quite easy views on RUclips. But not really great teaching.
Either way, I doubt this is going to change how anyone uses a torque wrench, and no fasteners will be harmed in people continuing to go about their merry way.
Hey Johnny, good video, But, one thing i have always been told it to always releive the spring by always reseting the torque limit back to zero to stop distorting the internal spring so it does go back to its normal length. keeping under pressue could change the springs strength. It this correct.
Yes, please, Mr. John. The home boofhead guide to recalibrating a torque wrench would be very educational. I keep both my Excaliburs in the blow-molded cases they came in, as well as any other precision-type tools that I have. I treat my tap-and-die set as if they are religious deities... I'm a bit pedantic about that.
Put a bearing in the middle of a 2m piece of suitably rigid steel tube (so it balances horizontally), bolt it to something solid through the bearing, weld a socket over where the bearing is to attach your torque wrench (vertically so its own weight doest affect the balance), make a weight, ideally in multiples of 1019 grams, put it on one end of the beam (1019g @ 1m from pivot = 10NM), put the scales under the weight (so that the beam is horizontal = important), apply torque to lift weight until wrench goes click at the multiple of 10NM you picked, hopefully scales read zero at that instant, if not, adjust accordingly. You dont "need" a bearing but it will be more accurate, a see saw on any pivot will also work fine but will be less tolerant of imbalance.
@@benchapman5247 Cheers,
@@BradGryphonn You could also just use a 1m (pivot centre to scales) horizontal beam with a torque wrench at 90 degrees, any weight and some scales but more calculations required. Also if you just use 1Kg @ 1m = 10NM to make it easier, you will be within 2% which your torque wrench probably would not notice anyway.
The existence of torque specs as the easiest way to replicate bolt stretch/clamping force is one of the most critical aspects of using a torque wrench. Arriving at your torque spec in one smooth, slow motion with the torque wrench will give you the best results. If you stop too close to the torque point, the higher static friction coefficient will make it impossible to get the bolt going again without clicking the wrench prematurely. Friction coefficient is also super critical, since bolt tension can be replicated with torque only by controlling the friction coefficient on the threads and under the head of the bolt. If an assembly procedure specifies dry fasteners, then any oil or grease on the threads or bolt sholder can cause significant fastener overstretch for the same torque value, and vice versa...like for front crankshaft bolts that specify oil on the threads and shoulder. It is very important, especially as the bolt tension increases...which is why often, very high tension fasteners like cylinder head bolts have a final tightening step in degrees rather than torque, as it becomes more and more difficult to replicate bolt tension versus torque as tension increases, but a given rotation angle will provide a definite strain distance determined only by the thread pitch. ARP provides a special extreme pressure grease for critical engine fasteners to improve the consistency of replicating the proper bolt stretch with a torque spec. Rusty dirty threads will cause a fastener to reach torque spec without enough clamping force, and putting antiseize on threads will require reducing the torque by a difficult to determine amount to not overstretch the bolt. Also, if you drill and tap a damaged hole to a different size and/or thread pitch, the original torque spec no longer applies, since the young's modulus, friction coefficient, thread pitch, etc are now all different. I prefer the flexible beam torque wrench for all critical/precision engine fastener torquing, as it is very consistent if used correctly due to how simple it is.
John, the torque applied to the outer tube is the same no matter the position of the grip. The torque is registered from the relative movement of the tube to the clicky bit against the spring tension. Changing the position of grip will only change the torque if the outer tube flexes differently with different grip positions, which it may for large forces. Obviously more force is required with a shorter grip, force by distance from the fulcrum, to achieve the same torque.
Try again. There are two different mechanisms with different fulcrums. Deal with it. Study basic physics.
@@AutoExpertJC - a Torque-off with a tube type vs a beam type wrench (most other "wrenches ": are called spanners - in Australia) may be a good thing to demonstrate the variance.
(yep - too true - the crowsfoot is supposed to be at 90 degrees if "torqueing" large fasteners..)
Good idea to back off the spring and treat an instrument differently to a tool. Cheap Mic's make half decent clamps - with a lock (HOWEESMACHINESHOP)
OK I went and did the maths - and a 2 body "analytical diagram". - Free body with moments and forces calculated.
(For kicks, uploaded a short to my channel. Link: ruclips.net/user/shortsz9AI0j4YSNA )
For a 100Nm applied to the "Primary Fulcrum", using a 50mm "clicker fulcrum offset" and a design length (handle middle) of 350mm (I forget what John said it was supposed to be - can't be rewatching everything.) At 350mm "grab length", For 100Nm on the wrench the Clicker activates at 85.7Nm, while for a "grab length" of 300mm the clicker triggers at 83.33Nm, and for a "grab length" of 400mm the clicker triggers at 87.5Nm, so plus or minus 50mm next to no difference.
- IF you apply the torque at the "clicker fulcrum" - infinite torque can be applied before the click is activated - the click sees Zero length moment arm.
(at a hand position of 100mm at 100Nm "bolt torque" the clicker is only up to 50Nm - so needs another 71.4Nm on the bolt before clicking - ie the bolt will be over torqued to 171.4Nm..)
John, your explanation does not make sense... if I place my hand to different position of the handle I change nothing, the only difference could be that with shorter distance of my hand I could have differnt sensitivity when the click comes... if you want to prove your point pls provide some diagrams to support it...
I agree. Effort is more but the distance from the second fulcrum to the clicky bit is the same.
Unless bending in the outer tube is significant (it isn’t, or the scale on the dial would be nonlinear), the detection mechanism is blind to where the force is applied. Dan2304 is right.
I'm a do it yourself mechanic dude, I always understood torque wrenches holding it every time in the right spot for proper torque.
on the matter of over torquing ( too much Peter Werrett) or whatever.
In many situations ( like cylinder heads) what matters above all, is that all the fasteners,, on that part,, are the same or very similar torque and thus tension.
Thus the mynnute accuracy of the torque wrench matters less than, that you used one, properly and consistently.
Totally agreed.
Great talk. I've got a couple of these things and never really knew how to use them. Now I do. Thanks Dude.
I would like to see your video on calibrating the torque wrench. In doing so, I would like to see you demonstrate how changing your hand position changes the calibration. I have my doubts on the latter and you could provide proof for sceptics such as myself.
On "I have my doubts": just go back in time and tell your baby self to try harder at school...
@@AutoExpertJCI have my doubts every morning, but then when I get in the shower and look down, something starts growing...
He told you why my man.
This style of torque wrench isn't measuring the actual torque at the bolt, it's measuring the torque offset some distance from the bolt and the manufacturer knows the relationship between torque at measurement and torque at the bolt. When you change where you hold the wrench it changes that relationship.
I think it's
Torque_actual = torque_measured × (r_actual/r_measured)
Make r_measured and r_actual shorter than what the manufacture assumes and the actual torque at the bolt will be higher than what you think it is.
If it were measured at the bolt it wouldn't matter because at that single location r_actual/r_measured will equal 1 no matter where you grab the wrench.
WOW, didnt know that, as I rarely use the thing. Glad I always used the handle in the past. Once you explained the two pivot points, with the pull apart demo visuals, it makes sense. Thanks John. Also, wouldnt mind seeing the calibration video!
I know your video was mainly for usage of the torque wrench. But I would like to add one thing. A torque should always be stored with no tension on the spring. I.e. back the handle off
Not necessary. Springs don't care what state they are stored in.
@@AutoExpertJC I've been told, that if you planning to store it for an extended period of time, it should be backed off to its lowest setting. Not sure if the advice is to save the spring, or not to affect its calibration. I'm talking for a torque wrench that used in production and gets calibrated.
@@PTS_Roller_Coaster_Case This is true. You want to store the wrench without any tension on the torque wrench spring. All springs can and will fatigue under tension over time if kept compressed. It is best to bring the spring back to its resting state when stored.
ChatGPT says otherwise and I suggest that leaving spring under tension is the most common reason for required recalibration. It was the first thing that came to mind when you showed me the guts. This is also a common problem with bike derailleurs stored in low gear with springs stretched.
@@kelvynbettridge
yep; relaxed setting is always best for storage, like with trolley jacks.
I like my old Warren and Brown single direction press pin torque wrench . Unless you have to tighten something in reverse they are brilliant
Love your videos John, and this one has gotten multiple views because I can't get my head around why exactly changing hand positions affects the torque measurement of the wrench because as I understand it, the wrench takes a torque measure and whether you put 100N at 50 MM, or 50N at 100MM, shouldn't affect what it tells you.
I can understand the torque offset caused by the actual measuring device of the torque wrench, the ramp, being in a different spot from the head which is where what we really care to be measured, but isn't torque equivalent throughout a system, or at least from an engineering diagram perspective it can be resolved anywhere?
Apologies for rambling on, but I'm curious if you have any more info for resources for understanding this.
This is how I'm seeing it too. I can't wrap my brain around how it would end in a different result. Not saying we are right tho. I wonder if he could do a demonstration of it so we can see the different results
It's like this:
1. You set the torque wrench. The mechanism goes click when a particular torque is applied.
2. If you put your hand in the right spot, the fastener experiences the torque you pre-set.
3. If your hand is out of position, it doesn't.
See, you think you're setting the fastener torque, but you are really setting the mechanism click torque. The fastener torque varies if your hand is not in the right place.
Click torque is an input (you set it). Fastener torque is a system response. The response varies with hand position. The wrench doesn't 'measure' anything.
Torques are only transferrable on rigid bodies, and the torque wrench is a mechanism. (Clearly it's not rigid. If it were, there could be no click.)
This is from Capri Tools: "Hold the wrench with the palm of your hand in the middle of the handle when applying force. If you hold the torque wrench at the end of the handle, the amount of torque may be less than what you need, even if the wrench is preset to apply a specific amount of torque. Likewise, if you hold the torque wrench too close to its head, you may apply too much torque."
I believe it has to do with the forces acting on the joint-pin and the click-point. If you apply force exactly on the click-pin spot, no force goes to the pin-joint on the bolt end, but if you apply the force near the pin-joint, almost all force goes to the pin-joint and not the click-mechanism. In the latter case the bolt still sees the torque applied by the force, but the click-mechanism does not trigger since there is no force applied in that point.
you are completely right. This guy's responses make absolutely no sense whatsoever, and he doesn't understand torque at all. Just like 99% of youtube mechanics...
Makes total sense. Ive only ever seen hvac guys use crows foot spanners with torque wrenches and probablyfor good reason even thought they also seem to like using swedish nut lathes.
If the inner and outer beams are rigid, the entire mechanism is blind to the angle and point of application of the external force. Where you put your hand will not make any difference.
FFS dude, try harder. This is very basic.
@@AutoExpertJC with the greatest of respect, have you performed any experiments? Analysed any data? Even sketched a free body diagram of any of the components? What would it take to change your mind?
The two beam mechanism is completely blind to what happens beyond the pin at the head behind the ratchet or socket driver. It has one input, that is the torque at the pin, one output of a normal force that eventually releases the clicky bit. You have sufficient torque wrenches (wrenchi?) there to put two together head to head, mount one rigidly eg in a tube in a vice, wrap the handle in rag and tape if you don’t want to scratch it, and read off the torque of the other for a given torque on the rigidly mounted unit, with your hand in various places along the shaft (heh heh heh).
I’ve only got one here, and it’s an ancient W&B, or I’d have a go myself. Instead of dishing insults, please either fortify your position empirically or analytically, at which point I say “wow, thanks for clearing that up!”, or accept that perhaps you need to rethink your standpoint; one of us is clearly wrong, but I’m not prepared to accept it on the basis of your saying I didn’t try hard enough in school.
@brianmonger8185 I'd admit, my thoughts were the same as yours. I'll admit that I am not very bright though.
Read the training manuals from Snap-on, Norbar and Capri tools, etc. This kind of torque wrench is length-dependent. Hand position really matters. This is called a fact, like gravity. No experiment needed.
Brian, experiments are unnecessary on something this basic. It's basic applied physics. Here's a quote from Capri Tools, which you can Google, to ensure I am not bullshitting you: "Hold the wrench with the palm of your hand in the middle of the handle when applying force. If you hold the torque wrench at the end of the handle, the amount of torque may be less than what you need, even if the wrench is preset to apply a specific amount of torque. Likewise, if you hold the torque wrench too close to its head, you may apply too much torque." I accept your apology. No biggie.
yep 90 degrees out is fine was what I was taught, plus release tension on the spring when storing and put it in the case, some newer torque wrenches seem to have a different mechanism where the spring type and calibration are more like an old-school bar type not needing any tension release because they're only under tension when tightening fasteners
Great video and learned a lot. Yes - how to "calibrate" a torque wrench. How about a video on "torque sticks", when best to use, and their (not so) accuracy. Again - thanks for this video.
I have been using torque sticks on automotive lug nuts for about 20 years and I find them to be plenty accurate when compared to either my click type torque wrench or my digital torque indicator. When I am changing a wheel in the field they are a godsend.
I have three Warren and Brown tension wrenches a 3/8th drive inch pound a 1/2 inch drive 0-200 ft lb and a one inch drive that I scored for free in the 1990s. I purchased the other two back in the early eighties. Note I am an Automotive Diesel Mechanic.
Calibrate good times, come on!
(Let's calibrate)
"It's a calibration!"
Iam very fortunate to have found 3 different warren and brown beam type torque wrenches. They'd all been abandoned either due to either being a ratchet style, or because the indicator pin retaining plug unscrewed and the pin fell out somehwere.
Spent about $100 buying new slide kits for them and cleaned them up. Love em, and very rarely do beam type wrenches go out of adjustment
Hi John, I disagree with you on this. The length relationship between the socket, the secondary pivot and the torque indicator (the clicky mechanism) remains the same regardless of where you hold the handle. If you want to convince me provide evidence using a strain gauge that there is significant difference in output torque at different hand positions.
I don't care what you think. This is a 'facts' thing.
Hi John, in that case, would you like to do a demonstration of these facts? I also have a different view on the relationship between the outer pipe and pivotpoint of the wrench. Sure the force required to reach a certain torque would be greater it you hold the wrench closer to the pivotpoint, but the clickwould still come at the calibrated value. I fully agree with your notion that there are 2 different torques at play here, but there is also the fact that the calibration takes care of this. Just my humble 2 cents here. Regards.
I did demonstrate the facts. You don't get a 'view' on this. That's absurd. It's like having a 'view' on gravity. Fascts don't give a fuck what your 'view' of them is.
From Capri tools: "Hold the wrench with the palm of your hand in the middle of the handle when applying force. If you hold the torque wrench at the end of the handle, the amount of torque may be less than what you need, even if the wrench is preset to apply a specific amount of torque. Likewise, if you hold the torque wrench too close to its head, you may apply too much torque."
Why don't you go have a 'view' about that?
Hi John, I will write to you at length off-line to explain your error. You have been hoodwinked by some slick ostensibly mathematical proofs that can be found on the net - try The Bike Sauce as a good example. The analysis of this needs to commence at the socket driver and proceed back to the handle. Hold your rude rebuttals - it’s physics. It’s just that you have been sold a pup dressed as a scientist.
I agree with John on this and you will too if you apply all your load at the secondary pivot point, you will still be applying a torque to the socket yet the clicky bit will never fire as the beam it is connected to is under zero torque around either pivot. The level of discrepancy changes depending on how far out you go but the load at the secondary pivot should be simple to see, understand and test.
Great Video John. I've always known how the click style wrenches work but never considered the dual arm equation - so I guess I actually didn't know how the wrench worked.
There is one other attribute that is extremely important in acquiring correct torque and that is the position of your arm while using the wrench. By definition, torque is measured at a 90 degree angle off of a rotating axis. Your arm must maintain a 90 degree angle all the way around your application. In other words, if you move your elbow inward toward the fastener, and pull toward that inward angle, the ending result will be too high; similar to choking up on the handle. I've also seen people use smaller wrenches (5-30 nm) and hold their forearm parallel to the wrench handle, affectively tripling the leverage arm distance of the little wrench. If they pull with their upper body from the shoulder, or sweep across with their elbow, the fastener is way under torqued.
This may be interesting to you: in the ski industry we test ski bindings for release tolerances. We basically use the torque wrench ’in reverse’ to calibrate the releasability of the ski binding. To do this we use beam type wrenches. We put a metal ‘foot’ in the ski boot that the wrench inserts into the top. Once the boot is placed in the binding, the wrench is used to twist the boot to the side, causing the toe piece to release. The wrenches indicator scale has little inserts in them that the ‘needle’ moves so that when the boot releases you can read the force applied by observing where the insert stopped on the scale.
Curiously, the beam type wrenches usually have floating handles with a pivot in the middle. You have to prevent either end of the handle from touching the shaft in order to maintain proper arm length. Too bad manufacturers didn’t keep this feature on clicker wrenches. It could be something to point out to the heretics - “Why would there be a floating handle if it didn’t make a difference”.
put a 6 foot tube on it , the torque will be the same to make it click
Yawn. Genius. Clearly the torque for the click never changes. It's the torque applied to the fastener at the click, which changes.
@@AutoExpertJC it doesnt
Good argument. Move over, Isaac Newton.
@@margarita8442 Yes it does.
I wish you explained this to me 40 years ago! What a great video!!! Thank you so much for this explanation.
This makes no sense. The force is being applied to the inner ratchet via the cam/roller mechanism, which is a fixed length ratio to the two different fulcrums.
I thought he made an april fool's video and mixed up the dates.
It makes perfect sense. Put your directional load at the secondary pivot and you have torque at the socket and no load on the clicker so it will never click no matter the torque load. Put your load at the clicker and you have 100% directional load on the click mechanism and nothing but pure torque on the secondary pivot. Put your load half way between them and you have half your directional load on the clicker and half on the pivot, the half on the pivot contributes no torque to the clicker mechanism but still imparts torque to the socket. The closer the secondary pivot is to the socket axis, the less the variation. It would make no difference only if the design of the wrench pivoted both tubes around the socket axis.
Thanks, John for filling me in on using my new torque wrench. Harbor Freight Chinese special on sale under US $20.
There is something I’m not understanding here so I’d appreciate your advice. The handle seems to me to be a rigid body so I thought the turning force you apply is determined by force times distance from the pivot. So 10lbf x 12in gives the same as 20lbf x 6in. Is my understanding that the handle acts as a rigid body rubbish? Cheers
There are two different pivots.
If both parts are rigid the entire mechanism is blind to the direction and point of application of force.
There might be two different pivots but the transfer of torque from the handle to the socket remains the same. The effort on the handle may not be linear because of the two pivot points but the resultant load back to the click remains the same because the click mechanism is at the same distance from the socket. John you have got this wrong!!
@wanajday I agree, at my work place we use a 5ft long tourqe wrench. Depending on torque setting used, it comes with a factory supplied cheater bar.
Clearly both parts aren't what you dudes erroneously call 'rigid'. There are two mechanisms. It's different to a rigid wrench, unless you're a moron.
I normally understand leverages and this sort of thing pretty well. I used to spend a lot of time studying snowmobile suspension linkages and generally have a pretty good grasp on these things... but I'm not able to connect the dots here. I will watch the other videos, as I believe you have two more... but as of now, I don't agree with this thought path.
First off, I actually tested my torque wrench the other day, because I didn't trust it (so maybe it is actually wrong). I used 22 pounds of water at one foot to test if it was accurate at 22 ft/lbs and it read perfectly, but the one foot location was not where you would put your hand on the handle.
My "argument" at this point in time, is that regardless of where you put your hand, the torque is applied between the roller mechanism and the centre of the ratchet head, and these two points never change. If you are torquing a bolt that requires 100 ft lbs with a two foot wrench, you will apply 50 lbs of force, and lets say 1000 forces to pop over the pin. If you choke up on it to 1 foot, you will have to pull on the wrench with 100lbs, and the same 1000 forces are still required to make the roller pop.
I think the best way to explain how I (likely incorrectly) think about this, is that the leverage on the fastener is always going to be from the center of the ratchet head to the clicker, regardless of where you put your hand. If you have a 50 foot pipe on the end of your wrench, it is still the load on the roller that actually determines the torque on the fastener.
Love your videos, by the way.
EDIT: I see that you make a habit of insulting people instead of just clarifying your point ... Reading some comments from others I can see how the pivot point of of the handle is not the same as the pivot point of the fastener...I'm very much a hands on learner... I was trying to imagine applying the force to the handle an inch from the handle pivot and how that would change the loads on the fastener vs the clicker... I'm pretty sure I get it now... but I'll still have to pull one apart.
"I think the best way to explain how I (likely incorrectly) think about this, is that the leverage on the fastener is always going to be from the center of the ratchet head to the clicker, regardless of where you put your hand. If you have a 50 foot pipe on the end of your wrench, it is still the load on the roller that actually determines the torque on the fastener. "
This is exactly what I was thinking too
Aaaannnddd guess what? We're right, of course, that's exactly the fuck how it works! You don't have to pull anything apart, or buy yourself a digital gauge or anything else, because you had it right from the beginning, this video just made you question what you already knew was true, which I guess is a good thing in a way, but a god damn annoying thing too, sometimes
@@trevors6379 I'm always open to the possibility that I'm wrong, but yes, how you explained this is exactly how I picture it... The torque is from the center of the ratchet head to the clicker... regardless if the handle is an inch or 500 inches. 🤷♂
Talk, Talk, Torque. to much talk and not enough action. Prove your point with a practical display, mate. Your correct, of course but show us how and why. Those that can, do. Those that can't, teach.
I don't have to prove anything. These are facts. It's up to you if you want to be dumb.
The theory presented here is so incredibly easy to prove or disprove that all I'm going to say is, test it yourself. Connect two torque together, hold the handles at different places, etc. Even put a cheater on one. Beam type, click type, electrical resistance type, expect interesting results. I did all this years ago in a shop, and there were some surprised mechanics.
exactly, it's really easy to disprove all of this bullshit
Warren & Brown? Had one 45 years - fabulous tools! Stunning explanation of Torque wrench mechanics / design. Many are also ignorant about gaskets eg: ya' can make one yourself from a cornflakes packet.
Excellent video sir. This was my first video of yours that I’ve seen and I really enjoyed it. You gave all the information needed in a clear way without a bunch of run time filters. Thanks.
Watching the kerfuffle, I see a lot of folks not willing to take on new information.
I admit, I would have thought that "choking up" would produce less torque, given we are told to choke up on a wrench to avoid overtightening.
Yet, this doesn't apply to the torque wrench due to the dual pivot points.
It is counter intuitive, but it does make sense given your explanation.
Great , clear presentation .
"Hand position really matters" ....thats what she said .
I'd also like to see recalibration video .
I think what is most important to understand here is. 1 if you use a torque wrench be sure you have the correct value and unit. 2 Use as intended. Generaly speaking in most applications fasteners don't come loose or break off if they are done up with some amount of care with or without a torque wrench. Problems are created from grossly over tightening or under tightening a fastener. Ive seen plenty of people damage things with a wrench and im sure it wasn't how they held it.
Ive been turning wrenches for almost 30 years. I rarely use a torque wrench because most things i can get pretty close by feel. But when i do, i use precision instruments split beam clickers.
I like how the ramping mech in the tube wrench is the same as my deflecting beam wrench, just implemented differently. I studied electronic engineering, but mechanical engineering is just as interesting.
😂When you get it right. Hope your electronics is not as lacking lol
@@petethewrist I chose the deflecting beam wrench over the tube wrench for its simplicity. You're right, though. I'm more familiar with electronics.
@@channelsixtysix066 I know nothing I have a GCSE in mechanical engeneering drawing. But it's could be deady if the wrong info is posted on other matters.
I like your channel in that you actually think sh’t through before spouting off.
How the torque range is defined by OEMs is where the rocket science is. Look forward to a beer garden analysis of that. Tip - it is not described in Shigley or any other generalised Engineering textbook.
They are also velocity sensative.
Keep that in mind when you watch those guys rebuilding a "top-fueller" in the pits between "runs".
I've used click-type and deflecting beam for years at home and work. D/B are superior and don't really ever go out of spec (ambient temps notwithstanding). I can add some advice for storage - always unwind the handle back to zero when you've finished using it. I have re-calibrated my own wrenches with luggage scales and some chord.
It's best to use measured volumes of water as calibrators.
Luggage scales are about as accurate as using MacDonald's Quarter Pounders
@PaulG.x to put this into perspective, how many cans of VB equates to a McDonalds quarter pounder?... shall we say ten?
Quater pounders are a lucrative business model since it is the weight of the meat before frying. Add a little water and fat which is what we don't know.
@@larrybe2900 throw in some sand for those who complain
Would like to see a video on how to bush calibrate a torque wrench. But a video on how wobblily extensions affect torque.
thanks I just watched this all. Much easier to understand than one I watched talking about physics:). I just checked a new cheapo wrench I bought, it had a calibration certificate march 2022! Supposedly 4%+- … Please can you tell me whether my test was correct?
1 . Digital Luggage scales checked by measuring 10L and 20L of water seemed accurate.
2. measure distance from centre of socket to line on knurled handle. (Should I have measured to the pivot point?)
3. Set wrench to 110Nm. Attach to fixed bolt pulled wrench horizontal at 90 degrees using luggage scales. Note value kg when click.
4 Calculate Nm and then swear as it’s waaay more than 4% out(9% to 14% low over multiple readings)
I did have an old wrench hardly used which was stored wound up and was also reading low so I bought the new one.
I had a go at calibrating that old one which seemed successful only 2% to 4% out but can’t trust it as I snapped the retaining cam of lock nut and may have dropped a ball bearing:) The 2 balls in the snap mechanism were still there though.
Your shop is pristine btw. My missus has one of those mats for cutting out material. It’s shocking pink and would look great in your shop:)
I've switched to those newer Snap-On electronic torque wrenches. Not because it's better or anything, more to do with speed and angle for torque to yield bolts. But more importantly, it's the yearly on-site calibrations from the tool truck.
The tool truck doesn't conduct calibration it only tests calibration and to meet the Australian standard torque wrenches need to be tested every 6 months at minimum
I never understood why hand position mattered because I assumed the clicky bit was somehow integrated into the ratchet head. This makes total sense.
Thanks for the video John. WB torque wrenches are truly a beautiful thing. I would definitely like you to to a calibration video.
Great video. You explained torque wrenches quite well. I'm asking this question in general. How do you know for certain the torque wrench gives correct torque when you buy it?
Parts wear and so do torque wrenches. Torque wrenches should be calibrated before the start of a project and every six months there after. Also after a project is complete calibrate it again to make sure it did not fall out of calibration while in use. I shudder to think you have to tear your engine apart because you discovered your torque wrench was off.
Was taught recently its distance from the wrench head (in cm) 39.8 x apply force (10kg) = 40nm. So if you got a bolt needing 120nm fasten you need 30kg at handle position distance aka 39.8/40cm
Good video John I’ve always had Warren and brown deflecting beam torque wrenches myself probably just old school.
Having said that a point of interest might be that some years ago I watched a video about the need for clicker torque wrenches to be “warmed up” for precision work and the way you do that is you put a fastener in the vice then incrementally work it up 10% from 0 to 100% and then back down again.
Something about putting adequate heat into the spring and softening any grease that may bind the spring in the handle………
No need for warming up with a deflecting beam
If you do need to use a crows foot or torque adapter, Norbar (lovely British torque tool manufacturer) has a brilliant app to correct the wrenches torque setting when changing length from the square drive 👍
en.wikipedia.org/wiki/Torque_wrench#Extensions
equations for various different situations, either extending or reducing the length of the arm at the head (ie crows foot), or putting an extension on the handle.
Yes I don’t think he covered that, as any offset from the square drive would have to increase the twisting force slightly beyond the torque setting selected. In a critical torque requirement that should be taken into account.
I've actually often wondered this when using mine if position matters. I always thought that it did because of how torque works. The longer the handlebar is the more force is applied. But how you described it actually uses a shorter handle and applies more torque which makes sense, but if you've ever cheated in cramped situations it's actually a lot harder anyhow.
Considering the mechanism of this type of wrench, I think it's really better to think of it in terms of force couples, rather than in terms of torques. Just think how the clicker mechanism would respond if you applied all the turning force exactly at the pivot of the clicker mechanism: it would "think" you're not applying any torque at all, even though you are!
😂The clicking bit by the nut does not have a clue as to where you hand is on the wrench. God reading lots of these replies I just can't believe how most of you have such a lack of everyday physics. Hope no e of you are mechanics. But then now I see why no one touches my cars but me. Not even the AA on the one time I called them out. Lol
Excellent video John and yes for a calibration video would be great. Thanks for sharing, Cheers
11:17 Thanks for the lightbulb moment! I had been scratching my head as to why it would make a difference where you held your hand on the wrench. Somehow I had imagined that the mechanism took effect at the ratchet head.
that was a very wrong explanation, which makes no sense. The force you apply on your hand will be greater, because you are now at a greater disadvantage. But the force needed for the clicky mechanism to go click, will still be obviously the same, no matter where you grab it. The clicky is independant of how far away you are grabbing it. It's just set by the spring force.
@@mikemx55 Ah, but the clicking mechanism clicks at a particular *torque* around its pivot point, so it is dependent on the distance. And because the clicky and the ratchet head have different pivot centres, moving your hand changes the torque on each by a different amount.
To take it to the extreme, imagine holding the wrench at the clicker pivot. You'd never be able to get it to click, no matter how much force you apply, even though you'd be applying torque at the ratchet head.
Thanks John, wasn't aware it made a difference. I always used the handle correctly regardless. Not going to pretend it makes 100% sense to me, but happy to have learned something new. Also first time seeing one apart. Love me a bit of insight :)
🎉where you place your hand makes no difference what so ever to the torque outcome to the nut
@@petethewrist you need to watch the part 3 of this torque wrench series. He proved you wrong there.
@@frantiseksram9741 no way can he go against facts. But I will watch it as it was a bloody good laugh. And all my mate have had a laugh to.
I watched it and he just spouted more crap. Make one wonder what else he has had wrong in past. I shell keep an eye on his posts from now on..
You’ve got me thinking now about all the bolts I’ve probably overtightened…
I started life as a physicist and initially I thought 'This can't be right!' I drew the force diagrams ....
Let's say holding the handle is case 1 and moving your hand up the shaft is case 2. Make Length1 & Length2 the distance to the pivot and d the offset of the drive axle.
To make it click, you need Force2 * Length2 = Force1 * Length1.
At the drive axle, the effective lengths are Leff1 = Length1 + d and Leff2 = Length2 + d.
The ratio of torques at the drive axle is thus T2/T1 = Force2/Force1 * (Leff2) /Leff1) = Force2/Force1 * (Length2 + d) /Length1 + d).
If a, b & d are all positive, some fairly simple algebra shows that if a < b, (a+d)/(b+d) > a/b. This means that (Length2 + d) / (Length1 + d) > Length2/Length1... so T2 > T1
So theory agrees with the measurements made by MrSleepProductionsInc below. Count me among the really surprised. 😄
Engineer here. Seemed obvious to me. Never expected it to be controversial. Verified it in part 3.
Metrologist/Calibrator Here,
18:45
Gonna go on a Nerd Out here but,
The biggest factor with the hanging weight Calibration method is having a scale thats accurate enough.
Within the industry, most Torque Wrenches have a 4% Tolerance from the Indicated Value for clockwise torque.
Example: 100 Ft Lbs = +/- 4 Ft Lbs
Here at my lab i got Torque Transducers from CDI, and that is connected to a display which shows the torque value. It is preffered that the Calibration Device is 4 times more accurate than the Wrench.
Back to the hanging weight method, you'd need a scale that can readout to about the hundredths place (0.01) or more. And you'd have to use the minimun amount of weights to snap or bend your torque wrench. And how much weight you use depends on the condition of the wrench. And youd have to applied the entire weight(s) on the hanger slowly and at once so you dont get excessive force from the weights flopping around or falling on the hanger.
Overall, the hanging weight method can be accurate if you have an accurate enough scale.
If you're in a shop where you get Inspected on your torque specs, id reccomend getting it sent in to Calibration.
Love the video! I Wish the operators on my site could watch this video haha
I made the mistake of watching the follow up to this first, not sure how you could make this any clearer. Well done
Excellent explanation of how to use a torque wrench....properly! Except in Canada, we use foot pounds, not Newton meters. :)
Show us how to calibrate a torque wrench.
Show us how to use a 1 metre long breaker bar as a torque wrench with a fishing/luggage scale to determine the weight you're exerting on the nut/bolt you're torquing down.
How to use the breaker bar as a torque wrench when it's less than 1 metre long. How do you convert the shorter distance to account for the greater/lesser force to correctly torque down your nut or bolt?
Get mechanics/engineers from race teams to come on and talk about how they did it in their apprenticeship days versus now, for instance.
The other thing people get wrong is the markings. A long discussion thread on reddit had people claiming they were nuclear submarine mechanics or aircraft mechanics but using the offset graduations wrong!!
This is taught in my torque certification classes. Hand position on the grip will vary the torque 1 to 2 percent for every inch off the center position and this is clearly demonstrated on a DTT (Digital Torque Tester). The DTT is used to field check a torque wrench and for training students in torque.
Agreed. It's obvious to anyone who's ever had their hands on tools professionally.
Does the outer tube deflect ?
Uneducated, son of an A grade motor mechanic, apprenticeship as a panel beater, like to think logically, or at least I thought I did 😮
If you're swinging on a ratchet, mechanical advantage comes in to play but can't wrap my head around the issue here
JC failed IMHO to explain
It's a physics thing. Here's a quote from Capri Tools, which you can Google to prove I'm not bullshitting you: Hold the wrench with the palm of your hand in the middle of the handle when applying force. If you hold the torque wrench at the end of the handle, the amount of torque may be less than what you need, even if the wrench is preset to apply a specific amount of torque. Likewise, if you hold the torque wrench too close to its head, you may apply too much torque."
I did not fail to explain this. You failed to understand it.
@@AutoExpertJC
It's difficult for people that lack engineering aptitude to grasp STEM stuff, like physics; I did a stint in the Army as a combat engineer and the Army did an aptitude test for all engineering applicants, which very clearly identified who would do well in understanding the theory and who would require being shown in real time on the tools, how things worked.
@@AutoExpertJC Didn't think you were bullshitting, however you did fail to explain it well IMO
It's a tricky thing to get the head around and I can understand someone getting it wrong. Try this, if you placed your hand right at where the pivot point is, you would need a lot of strength to tighten your bolt but the handle would have virtually no effort applied to it to set off the clicky bit.
Yes, but it will click at the same torque value.
@@DashCamSerbia In my example it is impossible for it to click as there is zero effort applied to the handle.
@allbeit582 Probably the best example of the mechanics of the principle here that doesnt require an understanding of physics that even the most skeptical can try at home.
We can score lower end Norbar models over 'ere in Britannistan for basically what one would pay for a "top end" Chinesium one. They're well built and very consistent, but there are no bells and whistles.
Hey John, thanks for the heads up on the novated lease on electrics i came across on FB. Ill be talking to them. Cheers