I have a total of 5 torque wrenches and we have them sent to an accredited lab (A2LA) for calibration. My question is, how often is calibration required and what tolerances are allowed? The lab rejected 2 this year and the 2 they rejected HAVE NOT been used since last calibration from the same company. Their explanation is "the tools are cheap and the "clicking" mechanism inside tends to wear out even if the tools are stored properly because the tools are such a cheap brand" We have to follow automotive guidelines (IATF and ISO standards) to calibrate and use of measurement equipment. We also have torque values required by the customer, depending on which installment is required, that the customer has set in place. The calibration company has suggested we "open the tolerance" on the rejected torque wrenches. I have no idea on what that is supposed to mean because we never set the tolerance. If they open the tolerance, would that no longer be an accredited calibration as it states in the IATF requirements? How would I explain that to an auditor if we go that route? Or what steps should be taken to resolve this?