Re: Torque Wrench question...

[Kevin Ford <chery_ford@bc.sympatico.ca>]

Frederic Breitwieser wrote:
> 
> 
> Beam type wrenches typically are more accurate than click wrenches, which
> after heavy use, the clicking mechanism tends to wear down hence its
> inaccuracies over time.
> 
> I've been building engines for years (with friends), and have both style
> wrenches, but I use the click style more often because I feel its faster -
> audible noise is much easier than reading the guage on the beam style wrench.
> 
> If you buy your Torque wrench from Sears or Home Depot (Husky Brand) they
> both have a lifetime warranty, and after a lot of use (5 years?) you can
> have it replaced free of charge, thus the inaccuracies go away.


The beam type torque wrenches Bentley refers to are the ones with the 
round gauge on them.  They are more accurate because the beam is much 
more stable than the compression spring and cam used in the click 
style wrenches.  Snap-On typically rates their beam types to 2%, while 
the click types to 4% accuracy.

Any torque wrench should be calibrated regularly.  Your tool supplier 
should be able to do this for you (Snap-On, Mac).  By the time you 
think it's "worn out", it's probably junk.  It's also a good idea to 
keep your wrenches clean, and moisture free (rust and crud on the cam 
of a click type wrench will effect the torque click points), as well 
as keeping them at the temperature they were calibrated at.

I use the click type wrench, as it is much quicker and easier, and a 
little more durable.

Bolt torque vs clamping force is an interesting subject, clamping 
force can vary alot (with the same torque) depending on the thread 
preparation (oiled, loctited, sealed, etc).  Hence the use of torque 
to yield  bolts in critcal areas.  (And my reluctance to bother with 
the beam type units)

Kevin Ford