5/16-18 x 3 1/2 Alloy Steel Flat Head Socket Cap Screw is used where the screw head must nest into an 82-degree countersink instead of standing proud of the work surface. The internal hex drive allows installation from above the workpiece, which is helpful in compact equipment where external wrench clearance is limited.

Maintenance teams use this configuration when replacing flush socket screws on guarding, covers, conveyor hardware, and other serviceable equipment. The alloy steel material keeps the product aligned with machine-building, tooling, and industrial repair requirements that specify this fastener family. The internal hex drive supports top-side socket engagement where side access is limited.

For this 5/16-18 thread and 3 1/2 in. length, the verified head data helps engineers compare countersink depth, head clearance, and tooling access. Cold Headers supports exact-size sourcing for specialty socket products and uncommon lengths used in industrial maintenance and production work.

Technical Highlights

• Material: Alloy Steel
• Thread Size: 5/16-18
• Length: 3 1/2 in.
• Nominal Body Diameter (B): 0.312 in.
• Head Diameter (A): 0.600-0.656 in.
• Head Height: 0.198 in.
• Hex Socket Size (J): 3/16 in.
• Minimum Key Engagement (T): 0.135 in.
• Drive Type: Internal Hex

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