MQP 2009-Statistical and Experimental Analysis of a Torque Model for Self-tapping Screws

A torque study is a series of lab experiments to determine the force needed to insert a screw into a given material. It is important to determine the torque needed to form threads and seat the screw (drive torque). Past MQPs have produced mathematical models of the self-tapping screw insertion process and developed a graphical user interface that takes in screw and material properties and produces a torque curve. In this work we performed 8 torque studies. We compare lab drive torques with WPI model drive torques using various statistical tests. We consider the effect of using a filter to smooth out the lab data. We investigate the modes of failure. We also determine the sensitivity of the WPI model. On this joint we find that the WPI drive torques fit well with the lab drive torques.