Machining Process Characterization for Breakoff Torque on Spinal Implants

Abstract

Abstract - Breakoff torque value on Spinal Implants is critical to ensure proper fixation of the system to the human vertebrae. Testing of manufacturing samples involves destructive testing which leads to scrap cost. The ability to predict torque results based on key process input factors not only reduces the setup times but reduces manufacturing costs as well while improving the confidence on the manufacturing process to produce parts that meets the specifications. This paper describes the statistical techniques and testing used to characterize the machining process of Breakoff Set Screws used on spinal implants. Key Terms - Breakoff Torque, Design of Experiments, Measurement System Analysis, Statistical Process Control.