ISO 6475Implants for surgery - Metal bone screws with asymmetrical thread and spherical under-surface - Mechanical requirements and test methods
ISO 6
475 provides a standard test method for determining the breaking torque and rotation at failure of metal bone screws. Test procedures for ISO 6475 are very simple, requiring that the screw be gripped to prevent slipping, torque is applied at a uniform angular velocity between 1 rpm and 5 rpm, and the ability to record maximum breaking torque and angle of rotation at failure. The test does not provide requirements for screw dimensions, but most tests are conducted on production screws meeting the HA, HB, HC, or HD specifications.