Topic: torque wrenches, I don't trust them

[MoTo-BunnY]

If  you don't trust your torque wrench, the correct procedure is the following: Torque the bolt 'til it strips then back-off 1/16th of a turn, that should put you in the ballpark

I always heard torque it 'till it strips and then back it off a quarter turn. .. .but maybe that's only for Kneuten joints or muffler bearings?   

[754]

Scott, this may be part of the problem.

When you first crack loose a fastener, I like to go about a 1/4 -1/2 turn or so, then stop and go back & forth a bit, to allow anything stuck to the thread to release..then wind out fastener. By hand you can feel what is going on.

Threads should be clean before reassembly, and running a tap down can be helpful. Also if you beadblasted..be really sure you got it out of the thread...and everything else..

[Wheelhorse77]

Scott,
   I just happen to calibrate TQ Wrenches for a living, for the last five years. I have to say if your wrench has been calibrated on at least bi-annual basis and used correctly it will not break or strip anything when the correct torque is applied for that item. One thing to think about is if the wrench has been dropped or misused it's calibration has more than likely been knocked out of whack. Also if you used any type extension, universal (angle) or crowsfoot (offset) they will need to be figured in to the equation because it will have a known effect on the torque value. You DO NOT want to lubricate, you always torque dry, lubrication will drive up the torque value on the item to which the torque has been applied. Another words torque a bolt dry to 30ft.lbs. and the TQ wrench will break at 30ft.lbs. and that is what you will have for an applied torque on the bolt. If you lubricated that same bolt even though the wrench would break saying the torque was 30ft.lbs. it would actually be a lot more than 30ft.lbs. and there is no known way to compensate for lubrication. The breaking type (click) is probably the most accurate and durable.

I disagree with the lack of lubricant in various applications. Bike head bolts or nuts require lube. Many( almost all) rod bolts insist on lubricant. Carrillo uses a heavy duty never seize compound, ARP bolts(ie Falicon rods) require either motor oil or their ARP lubricant, Crower rod bolts use moly lubricant. When it comes to aftermarket rod bolts a torque wrench isn't what you really want anyway. I use a stretch guage. The introduction of Locktite can change the torque value but many factory manuals recommend locking compounds AND put a torque value on the bolt or nut. Bottom line is follow the guidelines put forth by the manufacturer.

Are any of the after market bike parts you assemble require TTY or are you referring to assembling other automotive components that require an angle gauge?

[BobbyR]

I work in a Federally regulated industry and like Aircraft our Torque wrencheds need to be certified every six months. I teach torquing to our new hires. We use clicker wrenches and a few statements were made which may be partly true.

1. Every bolt has a wet and dry torque. A plated bolt has a different value than an unplated bolt since the plating increases thread dimension.

2. A clicker wrench should be stored at the lowest setting and not zero or at the last torque you used.

3. Many do not realize you need to hold the handle on the indicated spot and smoothly pull down not jerk the handle.

4. On a clicker wrench many people feel the click and keep pressing, you should let the wrench rebound in your hand at the click.

5.The maximum torque rating of a bolt should be only 80% of it's braking point. 

6. One of the problems today is bogus bolts made offshore, when you buy a grade 8 it can test out between 4 and 6 and they break.

& When you torque a bolt the last two turns should be done with the torque wrench. I have observed guys hit a bolt with an impact wrench and then put the torque wrench on it.

9. I personally like using a mild Loctite on all bolts on my bike since there is vibration and it helps insulate the dissimilar metals.

10. If I am bolting into aluminum I chase the treads before I put the bolt in. 

[canttuckmyshirt]

Can anyone recommend a brand of clicker? I had a Craftsman fail in under two years (stored correctly, never dropped/abused, used 5 times). They only cover is under a 1 year warranty and don't offer a repair service. I will not buy any craftsman products that aren't covered by their lifetime warranty.

Any recommendations? Thanks!

[bill440cars]

       I have a Snap-On 1/2dr torque wrench that is a ratcheting clicker type that I bough new back in 71'. I've always kept it in the heavy duty plastic case and I've always backed the tension off, when not in use.  I got it checked a couple of times when I worked in a Civil Service Shop on ARMY equipment and was always within tolerance. I was told that there really wasn't much use in getting it checked too often, since I take such good care of it. BTW, it still looks like new (remember, it is a 1971' model). Every now and then I have had it checked (last time was about 4yrs ago) and it was still looking good. I use this one for most of my torquing and I've got a Craftsman 3/8"dr beam type for smaller amounts of torque (my Snap-On has a range starting at about 35ftlbs). That's my experience with torque wrench.

                                 Later on, Bill    

[bert96]

I have 3 torques wrench 1/4  3/8 and 1/2dr  all Proto.I bought proto because my dad(he's a mechanic)  he have one for almost 30 years without any problem.I think when it comes  to have a precise reading you should pay more for a good tool.