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Socket Head Cap Screws

Socket Head Cap Screws

Socket hex head cap screws are externally threaded machine screws with an internal hex socket drive which corresponds to a hex key or allen wrench. Because the screws are internally wrenched, they require less surface area and are thus ideal for projects where there is insufficient space for traditional wrenches or sockets.

Socket cap screws can be either fully or partially threaded. On fully threaded varieties, the thread length equals the screw length, and the screw can be installed all the way into a threaded hole. Conversely, partially threaded set screws have an unthreaded portion under the head and therefore, the thread length varies. Because the unthreaded portion of the screw is stronger than the threaded section, partially threaded set screws possess more holding power when force is applied from the side.

Socket Head Cap Screw Types

Choose from five different hex socket head cap screw styles to fit your application.

Standard Socket Head Cap Screws

Standard socket head cap screws possess a cylindrical head with a flat, chamfered top surface and a recessed socket drive. The outer sides of the cylindrical cap are knurled. The cap can be situated either above the surface or recessed into a counter-bored hole. Ideal for precision assembly work as well as applications which require a neat, finished appearance, standard socket head cap screws offer a clean look along with maximum strength. Standard head caps are crafted from alloy steel, stainless steel, nickel alloy and silicon bronze. Available finishes include black oxide, zinc and plain while the majority of the standard fasteners conform to ASME B18.3, DIN 912 or Din 912/ISO 4762 specifications.

Low Socket Head Cap Screws

The head of low head cap screws is 50% smaller than a standard socket head cap screw and the internal socket drive is smaller. Available in plain steel or with a black oxide finish, low socket head cap screws are useful in applications with low clearance that will not accommodate the added height of standard head caps. Keep in mind, however, that though low head cap screws can be substituted for standard head cap screws, they cannot tolerate the same preloads. Low head caps are manufactured from steel, alloy steel and stainless steel and certain varieties meet either DIN 7984 or SIP 147 Specifications.

Button Socket Head Cap Screws

Button head screws have a low domed head with a wider bearing surface than standard heads, and they offer a finished appearance, making them an ideal choice when a neat appearance is desired. Designed for light fastening applications, button head cap screws lack the strength of standard socket screws. Fully threaded button socket cap screws are manufactured of either alloy or stainless steel to meet specifications outlined by ASME B18.3 or DIN 7380. Finishes include black oxide and oil, mechanical zinc and zinc-bake Cr+3.

Flat Socket Head Cap Screws

With a low-profile, countersunk head, flat socket head cap screws are ideal for applications requiring a strong fastener with a flush mount. For example, flat socket cap screws are often used in projects what require moving parts to pass over a fastened area. Because of their ability to mount flush with the surface, they are less apt to snag objects moving overhead. Flat head socket screws are crafted from either alloy or stainless steel with plain, zinc or black oxide finish and they are made to conform to ASME B18.3, DIN 7991 or ISO 10642 specifications.

AFT's socket cap screws are available in metric and SAE threads in a wide range of diameters and lengths. Use the menus to the left to narrow your search for the right socket head cap screw. Additionally, you'll find that most of the head cap styles are available with either nylon-patch or nylon-pellet self-sealing threadlocking modifications for added holding power. Our most popular products are the stainless steel socket head cap screws, but we also offer silicon bronze and Ni-Cu Alloy Steel. Should you not find the modification or finish that you desire on our website, please let us know. With on-site plating and coating facilities, we are able to customize any fastener with your desired modifications, including painting, plating, drilled holes and custom lengths. Contact us or request a quote to learn more from our experienced sales representatives.

Click HERE for additional technical information including: head dimensions, thread & body dimensions, and nominal screw length as well as performance and mechanical properties.

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