Per Proto's website:
Except as specified below, Stanley Proto Industrial Tools, a business unit of
The Stanley Works (“Stanley”) warrants any of its Proto and Blackhawk by Proto branded products for the useful life of the product against defects in material or workmanship.
Torque Wrenches, Torque Multipliers and Torque Testers are warranted for one year, except for calibration which is warranted for 90 days from date of purchase. Torque products can be repaired and recalibrated for a nominal charge at the Stanley Authorized repair center located at 2195 East View Parkway, Conyers, GA, 30013 or any other such location as may be designated by Stanley. Defects in material or workmanship will be repaired or replaced at no cost: all other repairs will be at a nominal charge. Torque products are precise measuring devices that require care in handling. Stanley recommends that all micrometer torque wrenches be recalibrated once a year or more, depending on usage.