Date:         Wed, 30 Nov 2005 09:31:29 EST
Reply-To:     THX0001@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         George Goff <THX0001@AOL.COM>
Subject:      Re: torque wrench
Comments: To: jfarrugi@UMICH.EDU
Content-Type: text/plain; charset="US-ASCII"

In a message dated 11/29/05 11:49:59 PM, jfarrugi@UMICH.EDU writes:

<< so i was wondering what recommendations the list had for a Quality and
economically priced torque wrench? >>

For economy and accuracy there is only one choice: a flexible beam type.  In
fact, if you buy a sensory ("clicker") style You should also buy a beam type
so that you can quickly check the sensory wrench before you use it.

A proper beam type torque wrench is a thing of beauty.  It is a direct
application of Hooke's Law which will last tens of thousands of cycle while fully
maintaining its original accuracy.  In fact, it will retain its accuracy right
up until the metal of its measuring element fatigues and it ruptures.  No
chance of using an inaccurate wrench there.  It does come with two drawbacks: using
one correctly requires a little practice and when using it around (and under)
a car it is sometimes difficult to swing the wrench and eyeball the scale at
the same time.

On the other hand, the convenience of a sensory style wrench is traded for
certainty.  And, the cheaper the wrench, the greater the uncertainty.  In my
experience, the uncertainty of the cheaper-by-the-dozen Pacific rim sensory
wrenches make them absolutely unusable.  Even if a cheap "clicker" wrench works at
first and even if it's setting is verified right before it is used, it will
sooner or later wring the head off a fastener whenever it fails to correctly
register its setting while putting the heat to the meat.

If you still want a sensory style wrench, spend the buck and buy a Proto or
Snap-On.  Even then you should plan to check the calibration every so often.
The calibration doesn't have to be certified, just check it against a flexible
beam wrench or rig up a simple deadweight tester.

George