To maintain consistent accuracy, torque wrenches must be checked periodically for wear or defective parts. A properly structured preventive maintenance program optimizes tool performance and reduces unexpected downtime, thereby saving time and money. After 5000 cycles or up to one year of use, whichever comes first, have your torque wrench inspected and recalibrated.
The more often a torque wrench is used the faster it will wear or go out of calibration.
The ratchet of a wrench should be inspected for wear, cleaned and lubricated. Periodically verify that ratchet screws are tight and that the ratchet spins freely when turned.
Protect your wrench from dust, grime, chemicals and other hazards by storing the wrench properly in a case or other storage device and keep it in dry and clean place. Clean your wrench on the outside with a dry cloth. External cleaning fluid or other chemical solvents can corrode the internal lubrication of the tool, causing premature failure.
Most click wrenches are built with an internal spring mechanism that is compressed to against a lever. Adjustable wrenches use springs that must meet a linear capability test. After use, externally adjustable click wrenches should be turned back to minimum scale value. This helps to preserve the linearity of the spring and calibration of the wrench. All calibrated wrenches should be backed off to the minimum setting when stored.
Do not exceed the recommended working range of the torque wrench.
Avoid dropping a torque wrench. If you suspect that a wrench has been dropped, have the tool inspected by a calibration service.
Do not use a torque wrench as a power bar to tighten or loosen bolts.
Avoid loaning tools. If a person that is borrowing a tool drops or damages it, they may forget (intentionally or not) to let you know.
Check shared tools before use. The simplest way to do this is to check the torque wrench against another wrench that is known to be in spec.
A torque wrench is a precision tool and should be treated and maintained like a measuring instrument.
