Originally Posted by
Rich@CCC
What most people don't do with their adjustable torque wrenches is exercise them.
As mentioned, they should always be returned to their lowest setting. Not past the lowest, not completely un screwed, the lowest designed setting. Then after setting to the desired torque, you should "exercise" the wrench by clicking it several times on a static screw or bolt. This ensures that the internal springs are all properly set.
They should also be calibrated periodically but I know of no one other than the Military and laboratory facilities that actually send their torque wrenches out for calibration. I know I've never had any of mine calibrated and haven't had any issues with my vehicles or scopes.
BTW, I use the cheaper FAT Wrench on for all my firearm needs. The Borka tools are far superior but I've had good results from the Wheeler tools