4-40 x 2 316 Stainless Steel Button Head Socket Cap Screw is selected when a compact rounded head profile and stainless construction are both important to the assembly. The button-head design gives engineers a compact rounded profile, a broad bearing surface, and internal hex drive access, while the 316 stainless steel material is selected where additional corrosion resistance is needed compared with general-purpose stainless grades.

Typical applications include marine equipment and dock hardware, where the rounded head helps reduce snag points while 316 stainless steel supports saltwater and coastal exposure. It can also serve instrumentation and control equipment, where the button head provides a finished appearance on visible panels and enclosure hardware. The button-head geometry is different from a standard socket head cap screw: it keeps a lower, rounded profile while still providing socket engagement.

For the 4-40 thread and 2 in. length, the reference head diameter is 0.201-0.213 in. and the head height is 0.051-0.059 in. Use the verified head dimensions below when checking surface projection, socket access, and replacement fit.

Technical Highlights

• Material: 316 Stainless Steel
• Thread Size: 4-40
• Length: 2 in.
• Nominal Body Diameter: #4 (.112 in.)
• Head Diameter: 0.201-0.213 in.
• Head Height: 0.051-0.059 in.
• Hex-Key Size: 1/16 in.
• Drive Type: Internal Hex

Reference dimensions may vary slightly by manufacturer.

Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.