Stainless Steel Socket Head Cap Screws (also known as Allen head screws) have a cylindrically shaped head with a flat top, knurled cylindrical sides and an internal hexagonal drive recess, often called an Allen or Hex drive. Socket Head Cap Screws have a compact head design making them ideal for use in tight or confined spaces. The internal hex (Allen) drive also eases their use in tight spaces by allowing easier access for the user to apply sufficient tightening force on the fastener during installation.

These fasteners are commonly used in applications where it is necessary to recess (counterbore) the head of the fastener, or in confined spaces that limit the size of the fastener head or that restrict access for the tool that drives the fastener. Stainless steel socket head fasteners made from 18-8 (300 series) Stainless Steel are commonly used in applications that require a higher degree of corrosion and rust resistance. They are often seen on food and chemical processing equipment. Stainless steel has a higher corrosion resistance than carbon steel and is also ideal for Marine environments. Thread lengths listed on this site are the minimum industry standard thread lengths. The actual thread lengths received may be longer than what is shown here. Socket Head Cap Screw length is measured from under the head, not overall length.