RE: Garage attendants...

["Dupree, Jim" <dupree@alldata.com>]

If you use the same impact wrench long enough you can develop a feel for how
much torque it applies based on where the dial is set. Accurate? No.
Functional? Yes. 
There are a lot of nuts and bolts that I tightened by "feel" with an impact
wrench over the years but critical fasteners I torque. Wheel lugs I would
typically run on with and impact to what felt to me as about 50-60 ft/lbs.
then I would go back and torque all the lugs with a torque wrench set to
proper spec. If the lug did not turn before I reached the torque setting I
would loosen it up and re-torque it. If you have ever had to cut off an
alloy lug nut from a Porsche because it was over torqued you would know it
is something you don't want to do again. Alloy lug nut over torqued to alloy
wheel they become one part and you have to use a hole saw slightly larger
than the stud diameter and cut the lug off with out damaging the high $$
Porsche alloy wheel.
Torque limiting extensions (Torque Sticks) and impact wrenches with torque
settings (there are some that have actual torque settings on them) are a
useful tools but should not replace a torque wrench for many applications.
When I was wrenching full time I had to have my ½" torque wrench rebuilt
about every year because it got so much use.

Jim Dupree

Note: a bolt will always require MORE torque to loosen it than what it was
torqued to.

		-----Original Message-----
		From:	Cynic5KS@aol.com [mailto:Cynic5KS@aol.com]
		Sent:	Friday, November 05, 1999 3:40 AM
		To:	quk@isham-research.freeserve.co.uk;
mchang@ece.nwu.edu
		Cc:	quattro@audifans.com
		Subject:	Re: Garage attendants...

		In a message dated 11/5/99 3:01:28 AM Eastern Standard Time,

		quk@isham-research.demon.co.uk writes:

		> > I just wanted to get this in the clear with people that
are wrenches for a
		>  > living.  I was told by a local shop that air
wrenches/impact wrenches 
		(you
		>  > know, the loud cool ones) can have torque-sensing
clutches or something
		>  > built into them so that they don't overtorque.
		>  
		>  You can get a kind of flexible extension that limits
torque.  IMO they
		>  don't work.
		>  

		I believe those extension to work... my NY mechanic uses
those.... everything 
		was around 80-90 ftlbs.  They are by no means very
accurate... 
		I still back them off and retorque them when i get home...
trust no one...

		Arden