In light of recent torque discussion

[Robert Deis]

More fuel to the fire:

> ----------
> From: 	Steve F
> Sent: 	Sunday, October 27, 2002 4:39 PM
> To: 	CO DSM
> Subject: 	[CoDSM] How to properly torque a bolt; research from top fuel and aerospace LONG
>
> Preface: bc of an out of spec wrench and reusing old
> turbo washers I had chronic turbo leaks which resulted
> in countless hours of replacing gaskets and turbines.
> After seeing "fast guys" who really knew their stuff
> lose hours and $$$ tearing apart engines bc of bad
> wrenches I a year ago I did some research on properly
> tightening a bolt[also called threaded fasteners].
> Some areas might seem like a bit much....until you
> have to spend hours fixing a problem bc, in my case, I
> had a torque wrench that was under by 10 ftpound at 52
> ftpounds. Important: this ignores the lazer/light $250
> wrenches made by Snap-on as the wasnt enough info to
> research these. (Part 2 in included below):
>
>
> ****part 1****
> Some important things to note - some of you, of
> course, know these:
>
> 1.)A summing you are a professional mechanic, you
> should have your clicker wrench checked every 8K-12K
> "cycles"(clicks) or every year.
> 2.)You should alway keep the treads clean. Incorrect
> thread torsion can result.
> will affect "torque" at the bolt head.
> 3.) Always pull the torque wrench towards you, dont
> push.
> 4.) Never use a torque wrench to loosen bolts.
> 5.) Always turn the wrench back to zero FT LBS for
> storage, If you dont the spring clutch inside will
> deform in its compressed state.
> 6.) Never drop it or beat on it like a regular wrench.
> Ever wonder why expensive torque wrench come with a
> rigid carrying case? Store it away from severe
> humidity and temperature extremes. For example dont
> store in your 30 degree garage and expect to get the
> right torque. Remember how small the springs are.
> 7.) Clicker types are good for usage in which the
> bolts will be in a high vibration environment. Bar
> types should be used for lug nuts; has to do with
> constant pushing which can trigger the release on a
> clicker.
> 8.) Never tighten a bolt with a non-torque wrench then
> attempt to check it with a torque wrench. I'll have to
> look this up again, but it has to do with static
> movements , how the clutch mechanism "feels" it, and
> its affect on a reading.
> 9) Get a wrench that is far out of your usage range.
> Using a 50 ftlb max
> wrench at 50 ftlb will throw off accuracy fast.
> 10) On Clean threads anit-seaze and other thread
> additive wont affect
> torquing.
> 11.) Get a square position to read from and get the
> wrench square on the head of the bolt. Dont use
> ujoints when torquing. Even though kits come
> with adapters, the "twist" of the adapter will affect
> torque. Any length adapters will effect torque. There
> is a calculation to overcome this.
> 12.) [editied out]
> 13.) This will calibrate fltlbs into inchpounds an
> many others. You need
> to haveJava on for it to work.
> http://www.boltscience.com/pages/convert.htm . So for
> instance if you wanted to tighten you flywheel to 100
> ftlbs and you have an inch pound
> wrench.....
> 14.) Having you wrench checked cost about $20 plus
> shipping.
> http://www.torquerepair.com/
>
> ****part 2(from a later post)****
> Well I just got my torque wrench(0-150 ft lbs).
> Originally when I took
> off the shrink wrap it had a very official sticker on
> it that said "inspected by 113324". Being that I had
> out of torque wrenches in the past, I figured I'd pay
> the $20 to be confident about inspector "113324"' s
> ability. Glad I did.
> Turns out my unused "inspected" wrench was out of spec
> by 10 foot pounds(under)* at a 90 foot pound setting
> and off(under) 12 foot pounds *[see below for detail]
> at 150 setting. It cost me $50 to have it fixed. They
> send you a "certificate of calibration" which gives>
> torque "as found" and torque set at " final"
> adjustment. with various other info like the room temp
> it was tested at. BTW this wrench was the $75 one sold
> by Pep Boys. Also, they call to discuss torque
> findings, nice guys, and he happened to mention that
> they find Asian made wrenches to be out of spec a
> significantly more then American made wrenches. Cheap
> labor?
>
> * the amount was calculated based on center spec. For
> example at 150 setting, in spec is between 156 - 144.
> Mine was 138 "as found" and 155 "final"(repaired). so
> it was off (144 + 156)/2 - 138 = 12 foot lbs(under).
>
> Steve Fantozzi

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