Socket Head Screws

2,000+ products

Expected delivery: Wed, Nov 18

Socket head screws are driven with a hex key, so they fit in tight spaces where a wrench cannot swing. Machine builders, tool and die shops and maintenance crews use them on fixtures, dies, motor mounts and guards. This section includes standard socket head cap screws, low head cap screws, button head and flat head socket screws, shoulder screws and set screws, in UNC, UNF and metric threads.

What to check before you order

  • Material. Black-oxide alloy steel is heat treated for high strength and is the usual choice for machinery. 18-8 and 316 stainless resist corrosion but are not as strong as alloy.
  • Head style. Standard heads give the most drive strength. Button heads have a low, rounded profile for guards and panels. Flat heads sit flush in an 82 degree countersink on inch screws and 90 degrees on metric.
  • Drive size. Check that your hex key set covers the drive. A worn key strips the socket, so replace keys that are rounded.
  • Set screw point. Cup point is the common choice for gripping a shaft. Flat point is used where the shaft will be adjusted often, and dog point locates in a hole or groove.

Common questions

How is a flat head socket screw measured?

Overall, from the top of the head to the tip, because the head sits flush with the surface.

See the fasteners category, machine screws for slotted and Phillips styles, and our thread sizes guide.

Socket Head Screws: page 26

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