Torque Wrench - What Type is This? Use or Don't Use?

Discussion in 'Maintenance/Repair' started by Busted Knuckles, Aug 14, 2015.

  1. Busted Knuckles

    Busted Knuckles Member

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    A got a hold of a torque wrench ... at flea market some years ago, I think.
    I brought it to some auto parts stores, and the clerks had never seen one like this.
    One guy said, "My grandpa had one of those.."
    ( Yeah, I feel old... )

    Anyway, it reads in pound per inch, not pounds per foot as manual specs follow.
    So to use it, take the manual specs in feet, multiply by twelve ( 12 inches = 1 foot ), and use that number with this particular wrench.

    Example: the torque specifications in Haynes Manual for a 20 R "Thermostatic Valve Bolt" is 15 lbs per foot. So in using this torque wrench, multiply 15x12 = 180.

    Is this correct?

    I understand that the numbers on this gauge wheel are so large that accuracy might not be the best method. So what are your perspectives?
     

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  2. jetas

    jetas Grand Toyotaholic

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    There is a way to convert but youre going to find limited times to use it on your truck.

    Do a google search on converting in.lbs to ft.lbs youl see what i mean
     
  3. MrDinkleman

    MrDinkleman Veteran

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    First of all it is Pound-inch, not "pounds per inch"

    The scale is in "inch-pounds" (the old, but correct IMO, way to say it) and you DIVIDE it by 12 to get pound-feet. So, you're correct, you need to multiply torque specs given in Pounds-feet by 12.

    The formula for Torque is Distance X Force, or R X F, in that specific order. If you've taken high school physics you would know that, that is read as "R Cross F", not "R times F" (which is different). Which is why I believe it should be read as "Foot-Pounds". But I digress...

    There are 12 inches in a foot so 1 pound-foot = 1 pound X 1 foot = 1 pound X 12 inches = 12 pound-inches.

    So your torque wrench has a range of 0-50 (=600/12) pounds-feet which is good enough for small fasteners like intake manifold bolts and oil drain plugs.

    Whether to use or not, if the scale dial turns so that you can zero it, AND if you test it to see if the torque values are close enough then, why not? Being calibrated in inch-pounds, it is much more accurate than a foot-pound torque wrench for low torque fasteners.

    HTH
     
    Last edited: Aug 15, 2015

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