Torque Wrench Accuracy

SuperDaveSuperDave Senior Contributor
in OFF TOPIC Posts: 3,249
How would a person check the accuracy of a torque wrench? Something a guy could do in his own shop. I have two that do not agree with each other.

Live in the past.... it's cheaper.

49 Super six Brougham

49 Commodore Eight Convertible

Melbourne, Florida


  • charles4dcharles4d Expert Adviser
    Posts: 347
    Buy a new one
  • Oldfarmer1947gmailcomOldfarmer1947gmailcom Expert Adviser
    Posts: 1,317
    There are lots of videos on the Internet. 
    This one is a valid in shop means to answer your question...

  • KdancyKdancy Senior Contributor
    edited March 30 Posts: 2,104
    A couple of things on the video. I would like to see the torque wrench tested at multible levels
    and in reverse mode. Unloading a torque wrench after use is essential to keeping its accuracy.
    How accurate is the electronic unit being used to test with, over time?
    I keep mine unloaded when not using and send  them to a pro testing company to have calibrated evey few years.  With an often used one, like in a dealership/mechanic shop, it is recommended to have calibrated once a year. Most people have no clue that they should be checked for calibration on an ongoing basis. One reason I've never purchased a used one.
    I send mine to Team Torque. Fast turn-around

    53 Super Wasp Coupe ready for restoration
    53 Studebaker Coupe Custom
    64 Champ pickup
    Wellborn, Fl
  • SuperDaveSuperDave Senior Contributor
    Posts: 3,249
    Thanks Old farmer. I purchased the calibration unit from Harbor Freight for about $25.00. I could have bought another new wrench for less $ but would probably end up with three different readings LOL. I haven't calibrated the adjustable wrench yet. My Craftsman 1/2 inch wrench works on the flexibility of the shaft and so far it looks like it's not so good either. Since there is no adjustment, I would have to create a correction chart. The breakaway wrench is a lot easier since you don't have to look at the wrench while torqueing. Working on a 39 ford flathead is a bit difficult to see while bending the wrench! So far I appears both wrenches are giving higher than correct readings.. makes me wonder how long that has been going on.. I think I will go back and re-torque my two Hudsons.

    Live in the past.... it's cheaper.

    49 Super six Brougham

    49 Commodore Eight Convertible

    Melbourne, Florida

  • jasejase Member
    Posts: 45
    Call the local small airport, and ask the mechanic where he has his calibrated. Regulations require tools used in aviation such as torque wrenches, cable tensiometers and the like, to be calibrated annually. And, if the FAA stops by, they want to see the calibration certificate. :)

    I am told that the Snap-on truck can check and adjust them, but he can't or won't give me a certificate, so I have mine done at an instrument shop.

  • FrankvintagefullflowcomFrankvintagefullflowcom Senior Contributor
    Posts: 929

    Re: HFT unit.
    There were many reviews of this item on HFT's site and I noticed a great number of bad ones, so I took a look. It appears that it's a pretty good product but is sadly underpowered.

    The following is a typical "one star" review. 

    Rated 1 out of 5 stars

    Known Battery Drain Design Problem - Stops working

    Submitted 19 days ago

    By BC

    From Middletown, NJ

    Verified Reviewer

    I like this unit when it works. I also experienced the same low battery and LO error as many others. With fresh battery, the unit stopped working properly after only a few times. It appears that the unit draws too much current from the CR2032 battery - especially when used with setting a torque value and triggering red LED and alarm. When red LED and alarm sounds the device displays LO and low battery symbol and stops working. Even when I set it to max torque and only used it to measure my torque wrenches, it still does same thing after about 6-10 uses in a row. Measured battery to be about 2.7 V. Returned for a second unit -- same thing happened. It appears the CR2032 battery does not have enough capacity for the normal device operation. I Contacted customer service and they stated that the device has an issue with the LO message and there has been no design change to correct this. Too bad - otherwise it seems to work well.


Sign In or Register to comment.