Alvord Polk 500 High-Speed Steel Counterbore, Built-In Pilot, Uncoated (Bright) Finish, 3/8" (On Size) Size
Counterbores are cutting tools that have a pilot to guide them into a previously drilled hole. They are used to form a recess or pocket for a socket head capscrew. These tools are of a solid high speed steel construction. High speed steel is a common general purpose material for cutting tools and is used to cut a variety of different materials.