ASTM F543 Annex A2 is used to measure the torque required to drive a bone screw into a test block made of rigid, unicellular polyurethane foam. The results obtained from this test bear no direct correlation to the torque required to insert a bone screw in human or animal bone. This method is used as a quality control check for maintaining product uniformity.
The basic test procedure for determining the insertion and removal torque is as follows: