TORQUE TENSION TESTING
The relationship between input torque and induced tension can be determined and the Nut Factor (also sometimes referred to as K factor) or coefficient of friction (μ or COF) can be calculated by testing in a load cell specifically designed for fastener testing. This test is commonly used to evaluate the effect of alternative fastener finishes, lubricants or to test the impact of re-sourcing fasteners. By controlling bearing materials, this test is also used as a substitute for in-joint torque-tension testing where fastener access, joint configuration or part availability prevent use of ultrasonics.
Although a quick internet search will provide K factors and coefficients of friction for many common fastener finishes, each of these can vary significantly and are best derived through testing. The team members at Peak are experts at the torque-tension testing techniques required to derive these values, including the ISO 16047 test specification.
Need K factor, nut factor, or coefficient of friction data? Do not guess, contact the experts at Peak for torque-tension testing!