4-40 x 3/8 Alloy Steel Button Head Socket Cap Screw is used where a rounded, lower-profile head helps keep exposed hardware compact without requiring countersinking. The alloy steel construction is practical for precision assemblies that specify a compact rounded head profile and internal hex drive.
Typical applications include material-handling systems and commercial equipment where the lower rounded profile helps limit snag points. It also supports guards and access panels when maintenance crews can remove covers without extra external wrench clearance. This head style is different from a standard socket head cap screw: it trades the taller cylindrical head form for a rounded button profile used on exposed assemblies.
For purchasing or maintenance records calling out 4-40 thread and 3/8 in. length, the reference head diameter is 0.201-0.213 in. and the head height is 0.051-0.059 in. The nominal body diameter and hex-key information below give engineers and buyers a quick check on fit, socket access, and replacement selection.
Reference dimensions may vary slightly by manufacturer.
Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.
