Should a mechanical "click" Torque Wrench be set to zero when not in use?

Question

I have a standard click torque wrench. I was told I should set it to zero when not using it in order to keep the accuracy high. Is this true?

Secondly, I have not been doing this since I purchased the wrench a few years ago, how much of a problem is that?

Answer 1

Yes you should store it at zero, it weakens the spring. I would have it checked/calibrated to make sure it is still accurate.

Answer 2

My Craftsman torque wrench cannot be put back in the box unless it's at 20%. Granted, the plural (or even singular) of anecdote is not data, but I have always heard 20-25% of the max torque it's rated for.

Answer 3

You might want to get your torque wrench calibrated. You might call your local maintenance facility at your airport. Torque wrenches used on aircraft MUST have an annual inspection sticker attached to the wrench, so most maintenance facilities do their own. If they don't, they can tell you where you can get it done.