It's funny Matt that you say QA requirements. I'm actually a QA Manager at a food processing facility and we do NUMEROUS Calibrations on different equipment/tools. Some are done daily, weekly, monthly, and yearly. If you are running an automotive business, I think getting your torque wrench calibrated at least once per year (I'd do it every month) should be sufficient AND you should have the factory spec sheet from the torque wrench manufacture stating that the wrench was calibrated correctly before shipping to your business. Also, if you run an automotive business, you should keep ALL your calibration sheets on file because if one of your customers crashes, gets injured, and sues because of a lug nut fell off after leaving your shop, you have proof that you have taken measures to ensure the accuracy of your tools.

Sorry for the lenghty discussion