Fred's torque wrench experiment

[Al Powell]

I just read Fred Munro's post: Torque: The definitive experiments.

In will try to set a good example by NOT RE-POSTING THE WHOLE THING!!!!! I
hope other listers who are fond of quoting multiple pages of text
(unnecessarily) will note this.

His key conclusion seems well borne out by his experiment - at least I can't
fault the method...
1. The length of the torque wrench does affect the torque generated at the
socket end of tool 2079 as predicted by Scott J and others.

Seems clear to me that there is some force at work OTHER than torque to
explain the difference in witnessed torque depending on the length of the
wrench used to apply force to tool 2079. I don't know what the term would
be, but the length of the lever used to turn the tool must be involved.
"Leverage"?   How does THAT work?????????  this was an interesting
discussion and experiment!

Remember that the original question was how tight to make the crank bolt
when tool 2079 was not available. Let's note that the phenomenon Fred
described does not apply to tightening a bolt *without* using an offset tool
such as tool 2079.  My practical suggestion still applies - just choose a
handle that's of a length that makes it practical to tighten the bolt. exact
torque is not critical at all, just cinch the sucker down to 350-plus
lbs/ft.

An aside: I have a friend who used to be an inspector at Boeing.  One of his
jobs was to witness the final torque on the main bolt holding the nose gear
on one of their jets.  If I recall correctly, the required torque was in the
range of 1200-1600 foot-pounds.  If memory serves, he said it took two guys
to apply the torque, and the wrench was more than 6 feet long.  In case
you're curious, the gauge showing the torque readout was in a dial above the
pivot point, and he witnessed the torque through an access hatch in the
plane above the nose gear.  He was extremely happy not to be near the bolt
in case a wrench ever slipped.

************************************
Al Powell
apowell at gocougs.wsu.edu
1958 Fiat 1200 Transformabile Spyder
1983 Datsun 280ZX Turbo
1993 Audi 90Q
1997 Chebby Blazer
1999 Chebby Blazer
************************************