Amazon.com $13.24 go to store Amazon.com Nylon 6/6 Set Screw, Plain Finish, White, Hex Socket Drive, Meets ASTM D4066/ASTM D6779, 1/4 Length, 1/4-20 Threads (Pack of 100) Set Screws are often used for holding a pulley, gear, or other parts from turning relative to a shaft.