Cup point Set Screws are headless screws whch are threaded the entire length. They have an internal hexagonal drive at one end and a cup-shaped indentation at the other end. The cup point is the most popular style set screw. Designed for fast, permanent and semi-permanent location of parts on shafts with hardness differential of 10-15 Rockwell C points and where cutting in of cup edge on the shaft is acceptable.