Torque Wrench Advice

[twr1776]

Thanks all for the advice, I think I will get a 3/8" in/lbs and call it a day. I have a 1/2" drive but tend to bulldog which is not a good thing for aluminum threads.

 

[49er]

Torquewrenches have (at least) two different kind of errors:
Missing repeatability and/or missing calibration.

With missing repatability throw it away, but it is fairly easy to recalibrate a torquewrench. (I have made a Low-tech presentation at: http://home20.inet.tele.dk/xxxxx/torquewrench.htm for inspiration).

Stig

A very practical calibration exercise Stig.
Your calibration integrity may be compromised by be the accuracy of your scales and the ambient air temperature during calibration. You should be well within the 10% of accuracy that is accepted as being the norm for most torque wrenches though. On a larger scaled wrench, at an indicated 500ft lbs, you could be actually torqueing 550 ft lbs.
On our GS's the head torque figure of 29 ft lbs, could increase to 32 ft lbs but that increase is not likely to break studs or strip threads.
The key is consistancy of torque.

 

[saddlewarmer]

Torquewrenches have (at least) two different kind of errors:
Missing repeatability and/or missing calibration.

With missing repatability throw it away, but it is fairly easy to recalibrate a torquewrench. (I have made a Low-tech presentation at: http://home20.inet.tele.dk/xxxxx/torquewrench.htm for inspiration).

Stig

Can you make the formula in ft lbs and in lbs for some of us?

 

[bwringer]

It's important to keep a firm grip on reality as well as your torque wrench. If your arm has a good idea of what 25 foot-pounds or whatever feels like, you'll be far less likely to strip threads.

You also need a good reality checker in your head -- it's pretty easy to misinterpret rows of teensy little numbers in a manual, so think carefully about the size of the threads and the materials involved before crankin' 'er down.

And lastly, make sure you understand the terminology -- I've seen tales of woe here from people who confused the size of the wrench (10mm) with the size of the threads (6mm), and applied 10mm worth of torque to a 6mm bolt.

With the smaller bolt sizes (6mm - 8mm and under), especially threads going into aluminum, I still prefer to tighten them very carefully by hand, using 1/4 inch drive tools wherever possible. There's a certain feel you develop after a while for when things start to go wrong. And at lower torque settings, you can't trust most torque wrenches.

 

[POULSEN]

Your calibration integrity may be compromised by be the accuracy of your scales

Are you questioning the accuracy of my wifes kitchenscale ?:-D

Can you make the formula in ft lbs and in lbs for some of us?

My best guess would be:
Replace Kg with lbs
Replace m with feet
Skip gravity
- and you will end up with ft-lbs

(But I might be corrected by some native non-metric:? )

Stig

 

[49er]

Are you questioning the accuracy of my wifes kitchenscale ?:-D


Stig

I guess it all depends on how prolific she is at cooking. \\/

bwringer, you're right about judging the torque by feel. I never use a torque wrench for bolts in the 5-12mm range. In fact, I have only used a torque wrench for tightening down heads, automotive gearbox and diff internals and flywheel nuts on mazda rotary engines.
When using a ratchet on the smaller bolts, I reduce the leverage by holding the ratchet pivot area in the palm of my hand. You get good feedback and reduce the risk of over tightening.
I must admit to stripping the odd thread in the early years. It's all part of the learning curve. You can't gain experience by just reading about it.

 

[Guest]

I have a 120ft.lb. 3/8 snap-on that the anvil (the square part that the socket attaches to) broke off of it while set and used at 95ft.lbs.

 

[BadBillyB]

Tried to avoid this topic, but I figured I would throw my 2 cents in. I have 3 torque wrenchs, 1/4" drive in./lb, 3/8 drive ft/lb., and a 1/2" ft/lb wrench. They are all Snap-On "clicker" type and I have them calibrated every few years. The best tips I can give you are....
1) The torque spec you are working with should fall right in the midle of the range of the wrench. If you are torqueing the bearing caps to say 90"lbs., than the ideal wrench would have a range of 0-180" lbs. This is where the wrench is most accurate.
2) Make sure the threads/surfaces are lubricated with motor oil to lower the friction factor
3) Torque should be reached while the fastener is being rotated. Meaning, if you stop turning before the spec is reached (to reposition) and the wrench "clicks" before the fastener begins turning (after repositioning).....loosen the fastener and re-torque it. In other words, if you are torqueing the cylinder head nuts, and you are going for 30ft lbs and you stop at 26ft lbs to reposition the wrench, it may take 35ft lbs to just get the fastener moving again....Loosen slightly and re-torque
4) If you use "clickers" like I do, store them with them set at the lowest setting, it keeps the spring from losing its tension
5) If you are torqueing a bolt into a "blind" hole, (like the cam bearing caps) make sure there is no liquid (oil) in the hole. You can not compress a liquid and the threads will be ruined by the "hydraulic" action.

BadBillyB

 

[runewolf]

I hate to ressurect an old post, but I'm curious about what you guys think about this wrench? I've got to beg borrow or steal a torque wrench to replace gaskets in my bike

http://www.amazon.com/Neiko-Pro-PROFESSIONAL-Automatic-Torque/dp/B000LNDCXS/ref=sr_1_19/102-9553055-8996140?ie=UTF8&s=hi&qid=1180033493&sr=8-19

 

[rustybronco]

where are you located?

 

[runewolf]

Buckhannon, WV (Small Town, USA)

 

[north49]

I use a Snap On 3/8" drive "clicker type" 0-75 ft/lbs. Short handle, precise, and a beautiful thing! part # QFJR 275 D.

cheers

 

[frosty5011]

I hate to ressurect an old post, but I'm curious about what you guys think about this wrench? I've got to beg borrow or steal a torque wrench to replace gaskets in my bike

http://www.amazon.com/Neiko-Pro-PROFESSIONAL-Automatic-Torque/dp/B000LNDCXS/ref=sr_1_19/102-9553055-8996140?ie=UTF8&s=hi&qid=1180033493&sr=8-19

Piece of Junk............I'm sure Keith will agree with me, that this is the only way to go:

:-D

 

[rapidray]

All of my torque wrenches are click type Snap-Ons & EVERY time I have taken them in for calibration they have never needed it! I use all 3 almost DAILY & have inch pound, 0-75, & 25-250. I truly believe you can't go wrong with Snap-On! Just remember, if you ever drop your torque wrench have the calibration checked before using. Ray.

 

[runewolf]

I know Snap on makes great stuff and I know I can usually take them back to the Snap on driver down the road from me and get a replacement if it breaks, but good lord, can't you buy anything of quality for less than $100 these days?

 

[KEITH KRAUSE]

Piece of Junk............I'm sure Keith will agree with me, that this is the only way to go:

:-D

I agree. That would make a decent breaker bar.

 

[BlackStar]

Accuracy: ? 4% clockwise ? 6% CCW of indicated value, CW, from 20% to 100% of full scale

These are the spec's for a CDI torque 30-200 "# torque wrench I bought a while back for about $100.00. I tend to get more concerned about accuracy on the smaller critical fasteners like cam caps, etc.. For the larger stuff I just use craftsman clickers. As with any torque application proper thread prep, care of the wrench, using it in it's reccomended range (usually 20 - 100% of full scale), storing set to lowest setting (or whatever mfr reccomends) will ensure good results. At work (aerospace) we use snap-on's calibrated to +/- 3% of indicated value, which they seem to have no problem meeting, but I can't afford all snap on at home! Just my .02.

Here is a good site for ref.

http://www.cditorque.com/main.html

See Torque facts section.