Value Collection 721176PR Flat Socket Cap Screw 5/16-18

Product Description

The VALUE COLLECTION 721176PR is a flat socket cap screw designed for flush or countersunk fastening applications in metal assemblies. The 82-degree flat head seats fully into a countersunk hole, keeping the mating surface smooth and unobstructed. Drive engagement is through a 3/16-inch hex socket. The fastener is manufactured from alloy steel with a black oxide finish, which provides moderate corrosion resistance and reduces light reflection in service environments. The 5/16-18 UNC thread and 3-1/2-inch overall length make this screw suited for moderate-depth assemblies where a partially threaded shank is required. Sold in multiples of 10.

This flat socket cap screw is used in general industrial, mechanical, and structural assembly work where a recessed, low-profile head is needed. The partially threaded shank allows the unthreaded portion to act as a shoulder, improving alignment and shear resistance in bolted joints. Typical applications include machine frames, tooling fixtures, jigs, and fabricated metal components. The black oxide finish suits indoor or protected environments. Installation requires a 3/16-inch hex key or socket drive.

Key Features

• 82-degree flat head profile for flush countersunk seating
• 3/16-inch hex socket drive for positive torque engagement
• Partially threaded shank for improved joint alignment and shear resistance
• Alloy steel construction for high tensile strength
• Black oxide finish for moderate corrosion resistance and low reflectivity
• Meets ASME/ANSI B18.3 and ASTM F835 fastener standards

Compatibility

Designed as a standard UNC replacement or new-installation flat socket cap screw for assemblies requiring a 5/16-18 thread, 3-1/2-inch overall length, and an 82-degree countersunk flat head per ASME/ANSI B18.3.

Installation Notes

Installation is typically performed by machinists, millwrights, or maintenance technicians using a 3/16-inch hex key or T-handle driver. Ensure the mating countersink is machined to an 82-degree included angle before installation. De-energize or lock out any equipment before fastener service per applicable OSHA lockout/tagout procedures. Do not substitute a hex key with a worn or undersized tip, as this can damage the socket drive recess.