Torque to Turn Testing
Torque to turn is a measure of the turning moment required to make one component rotate about another. Unlike measuring torque (shear) strength, there are two factors at play: breakaway torque – or what it takes to initiate rotation, and running torque – or what it takes to maintain rotation. In the case of fine bearings, for example, the breakaway or starting force can be critical where the running torque is extremely low. Running torque is the key measure of the torque required to keep one part rotating against another. As a sustained effort this can measure the resistance in a system. However, when measured in detail it can provide a signature that indicates smoothness or running, lack of concentricity, or defects resulting in observable ‘chattering’.
Related test types
Torque to turn test standards
A number of standards for torque testing have been developed. For example:
- ASTM D1478-07 Standard Test Method for Low-Temperature Torque of Ball Bearing Grease
- ASTM D3198 Test Method for Application and Removal Torque of Threaded or Lug-Style Closures
- ASTM D3472 Test Method for Reverse-Ratchet Torque of Type IA Child-Resistant Closures
- ASTM D3810 Standard Test Method for Minimum Application Torque of Type IA Child-Resistant Closures
- ASTM F2213-06 Standard Test Method for Measurement of Magnetically Induced Torque on Medical Devices in the Magnetic Resonance Environment
- ASTM WK15535 Rotational Capacity Testing of Plain or Coated Bolt, Nut and Washer Assemblies
- BS EN 1707:1997 Conical Fittings with a 6 % (Luer) Taper for Syringes, Needles and Certain Other Medical Equipment. Lock Fittings
- BS EN 20594-1 Conical Fittings with a 6 % (Luer) Taper for Syringes, Needles and Certain Other Medical Equipment. – General Requirements
- ISO 594-2 Conical Fittings with a 6 % (Luer) Taper for Syringes, Needles and Certain Other Medical Equipment. – Part 2: Lock Fittings
