A higher-grade threaded fastener with a finished head, typically a hex cap screw with a washer face under the head or a socket head cap screw driven by a hex key. Compared with a plain hex bolt it has tighter tolerances on body diameter, head height and thread length, so it can go into tapped holes and close-fitting assemblies. In inch hardware, the finished hex part sold as Grade 5 or Grade 8 is a hex cap screw even when everyone calls it a bolt.
Grab a half-inch hex cap screw, Grade 8, two inches long, and run it into the tapped hole on the bracket.
Look under the head: a small raised washer face is the usual giveaway of a hex cap screw rather than a plain hex bolt.
Also heard as
- hex cap screw
- HHCS
- finished hex bolt
Related terms
Bolt
A headed, externally threaded fastener meant to be tightened by turning a mating nut rather than its own head.
Screw
An externally threaded fastener tightened by turning its head, into a tapped hole or a thread it makes itself.
SHCS
Socket head cap screw: a round-headed, high-strength screw driven with a hex key into a tapped hole.
Heavy hex
A hex head or nut wider across the flats than the regular series, used for structural and pressure bolting.