What is a Set Screw?

A set screw is a type of fastener used to secure one object within or against another without using a nut. It is typically threaded along its entire length and is driven into a tapped hole. Set screws are most often used to hold pulleys, gears, or collars on a shaft to prevent relative motion. Unlike bolts or traditional screws, set screws are fully embedded in the material and usually do not protrude.

Key Features of a Set Screw:

• Fully Threaded Body: The entire length of the screw is threaded for maximum holding power.
• No Head: Set screws often have no head and are driven using an internal drive (like a hex socket).
• Pointed or Flat Tip: Available in various tip styles—cup, flat, cone, dog, or knurled—for different holding strengths and applications.
• Compact Design: Designed to sit flush or below the surface for a clean and unobtrusive finish.
• High Grip Strength: Provides a firm and secure grip, especially on round surfaces like shafts.

Common Uses of a Set Screw:

• Securing Gears or Pulleys: Used in machinery to attach rotating parts onto shafts.
• Fastening Knobs or Handles: Common in tools or instruments where a tight, hidden fastening is needed.
• Preventing Movement in Assemblies: Used in collars, couplings, and mechanical assemblies to prevent motion.
• Electronics and Instrumentation: For precise, secure component positioning.
• Automotive and Aerospace: In applications where vibration resistance and minimal projection are required.