Thread Forming in Lightweight Material Joints Using Self-Tapping Screws

Abstract

In this study, thread forming performance is evaluated under cyclic heating and cooling of tapped lightweight multimaterial joints in which steel self-tapping screws are used. Joint performance is assessed in terms of residual torque, pullout strength, load transfer capacity (LTC), and failure mode. Cyclic temperature fluctuates between 130 °C and −20 °C in a computer-controlled environmental chamber. Joint coupon materials are steel and Nylon polymeric material. Data analysis and discussion are provided. Analysis of experimental data provides a useful insight into design optimization of self-tapped joints.