Torque Wrench

Discussion in 'Ranchero Tech Help' started by Huevos, Apr 9, 2015.

  1. Huevos

    Huevos In Maximum Overdrive

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    What is the consensus on Digital Torque Wrenches?
    Yea or Nay?
    Eastwood has one I've been looking at..
     
  2. Billy Zoom

    Billy Zoom In Fourth Gear

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    I only trust the old beam types. They might not be as accurate, but at least you can see if they're working.
     
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  3. ribald1

    ribald1 Banned PLATINUM MEMBER

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    Strain types should be just as accurate, if not more so than the other types.
    All become inaccurate with use and need to be tested periodically and either adjusted or replaced.
     
  4. Billy Zoom

    Billy Zoom In Fourth Gear

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    You'll never break a bolt off because a strain gauge wouldn't click when you reached the correct torque.
    I had an expensive one lock up on me the first time I used it. I got a replacement, but I never fully trusted it. I always try it on the bench vice first, and I still use the beam wrench on smaller fasteners.
     
  5. vmaxman

    vmaxman In First Gear

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    I like the digital wrenches for certain jobs like bolts on my Yamaha VMax or my Honda CBX.
    I got a Craftsman digital at a flea market for $25.00; PMEL lab at the base tested it and was .02% off actual cal. Not a bad deal.
    I use the break-away on the lug nuts and heavier work
     
  6. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

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    Much as I am not a MOPAR man, I talked to a former Chrysler engineer once a long, long time ago, and he said that beam torque wrenches are the only type Chrysler uses in any capacity, because dropping one does not throw it out of whack, whereas a strain gauge takes a beating on one drop.
     
  7. mo.herbfarm

    mo.herbfarm In Maximum Overdrive

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    I learned while doing strain gage installations on head bolts that the torque/tension relationship in threaded fastener work is quite variable. Condition of thread surfaces as well as the load-bearing under-head surface, and the "slipperiness" of the threads, whether lubricated or not, all affect the tension, or bolt stretch, achieved.

    FWIW, the typically-used formula relating torque/tension for steel is: T = 0.2 F d, where T is torque applied, F is the tensile Force produced, d is the nominal diameter of the bolt (like 1/2", etc.), and 0.2 is a factor which varies with the conditions above, but generally is close with average surface finishes and lubricated threads. Re-written as
    F = T / 0.2 d, given a 1/2" steel bolt, torqued to a value of 80 ft.-lbs. (which is 960 inch-lbs, to keep units consistent, the bolt tensile force would be 9,600 lbs. This would result in an approximate tensile stress level in the bolt of 48,900 psi. That number is no problem for a typical grade 5 or better bolt. mo.
     
  8. Huevos

    Huevos In Maximum Overdrive

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    What kind of math uses letters? I hate math.....LOL
     
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  9. TestDummy

    TestDummy In Maximum Overdrive SILVER MEMBER

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    That may have been true in the 60's. You will not see a beam torque wrench in any OEM test lab today; they are all click or digital, but they do routinely calibrate them. Something backyard mechanics rarely do.
     
  10. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

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    Well, this was in the late Nineties that I talked to him. So it is a bit newer. However, if what you say is true, It only means only the individual OE companies do their own cals (even though there are standards, there are also tolerances to them) and so who knows just how far off the tools are? And IIRC, a beam-type is what is used to check a strain gauge-type's cal anyway.
     
  11. MaxInValrico

    MaxInValrico In Maximum Overdrive GOLD MEMBER

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    Algebra, Trig, calculus. Letters are used to represent variability or in other words, plug in your value. Symbols are used to represent constants, such as pi.
     
  12. MaxInValrico

    MaxInValrico In Maximum Overdrive GOLD MEMBER

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    . That's why you have both. Can't have too many tools.
     
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  13. Huevos

    Huevos In Maximum Overdrive

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    MMMMM,,,Pi
    [​IMG]
     
  14. mo.herbfarm

    mo.herbfarm In Maximum Overdrive

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    Success! Another cluster-f#*k begun! mo.
     
  15. TestDummy

    TestDummy In Maximum Overdrive SILVER MEMBER

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    You seem to have a knack for starting threads nobody wants to follow ;)
     
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  16. MaxInValrico

    MaxInValrico In Maximum Overdrive GOLD MEMBER

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    Rock n roll homie.
     
  17. mo.herbfarm

    mo.herbfarm In Maximum Overdrive

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    That's cuz' I provokes 'em, then they really starts thinkin' how to out-fox me, then fireworks start, then I finish my beer and drift off to sleep, awaiting tomorrow morning's results............. :rolleyes: mo.
     
  18. Jeff B

    Jeff B In Maximum Overdrive BRONZE MEMBER

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    Got to love a hobby that involves beer.
     
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  19. TestDummy

    TestDummy In Maximum Overdrive SILVER MEMBER

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    They? :cool:
     
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  20. ForistellFord

    ForistellFord In Maximum Overdrive GOLD MEMBER

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    All my hobbies involve beer. Some don't even involve the hobby.
     
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