Socket Products Basics

Socket products are fasteners that have an internal hex drive for use with a hex key, or Allen wrench, which requires very little clearance around the fastener. Socket fasteners include screws, bolts, set screws and shoulder bolts. Socket products are widely used in industrial production and assembly lines, including automotive, furniture manufacture, machine tooling applications and steel fabrication.

Socket Head Cap Screw

Socket head cap screws (also known as Allen head screws) have a cylindrical head with a flat chamfered top surface, knurled cylindrical sides and hexagonal recess. A key feature in the design of a socket head cap screw is the ability of the head to sit down into a recess, as no clearance around the OD of the head is required for wrenching.

Flat Head (Countersunk) Cap Screw

Countersunk socket head cap screws are designed to recess into an 82° counter bore for a flush installation, with the hex key offering a more effective drive when compared to other drive types (such as phillips or slotted).

Button Head Machine Screw

Button head machine screw have a wide range of uses, designed for light duty applications such as securing guards, covers, and ornamental fixtures. Most button head screws have no stamping or marking, which presents a pleasing appearance to an assembly.

Socket Shoulder Bolt

Socket shoulder bolts are very specialized. Sometimes called stripper bolts or just shoulder bolts, have a smooth shoulder that is larger than the thread diameter, running down the majority of the length of the fastener. The shoulder, having a larger diameter than the threads, allows the fastener to be used in rotating applications such as pulley shafts, bearing pins, axles, and pivot points. The thread length is standard for a given diameter. Unlike most fasteners, socket head shoulder bolts are not sized by the thread diameter and length under the head, rather the diameter and length of the shoulder itself.

Square Head Set Screw

Square head set screws, also known as jack bolts, are fully threaded fasteners with a square head and most commonly, a cup point, though other types of points are available. They have a large wrenching area that provides positive gripping for a hand wrench. They are ideal for holding pulleys, collars, and other machinery shafts where fine adjustments are necessary.

Socket Set Screw

Socket Set Screws are a headless fastener threaded its entire length (except for the point) used commonly for fastening mated parts such as a shaft and collar. These set screws are intended for compression applications only and are not customarily subjected to embrittlement tests. The socket set screw's headless design allows the fastener to sit flush, or inset, into the threaded part.