Value Collection 721587PR Flat Socket Cap Screw 4-40

Product Description

The VALUE COLLECTION 721587PR is a flat socket cap screw designed for applications requiring a flush or countersunk fastener profile. Manufactured from alloy steel with a black oxide finish, this screw features an 82-degree flat head and a 1/16-inch hex socket drive. It is fully threaded along its 7/8-inch overall length with a 4-40 UNC thread. The black oxide finish provides mild corrosion resistance and reduces light reflection, making it suitable for precision assemblies, jigs, fixtures, and light mechanical applications where a low-profile head is required.

This screw is suited for use in metal fabrication, instrumentation, electronics enclosures, and general mechanical assembly work. The 82-degree flat head seats flush with or below the surface of the mating material when installed in a properly countersunk hole. It is commonly used by machinists, maintenance technicians, and assembly professionals working with tapped metal components where a recessed fastener is needed to maintain a clean surface profile.

Key Features

• 82-degree flat head for flush countersunk installation
• 1/16-inch hex socket drive for precision torque application
• Fully threaded 4-40 UNC along the entire 7/8-inch length
• Alloy steel construction for strength in light-duty fastening applications
• Black oxide finish for mild corrosion resistance and low-reflectance appearance
• Meets ASME/ANSI B18.3 and ASTM F835 fastener standards

Compatibility

Designed as a standard 4-40 UNC flat socket cap screw for use in any tapped or threaded hole conforming to 4-40 UNC thread specifications and a countersunk seat machined to accept an 82-degree flat head.

Installation Notes

Installation is performed with a 1/16-inch hex key or ball-end hex driver. The mating hole must be tapped to 4-40 UNC and countersunk to 82 degrees to achieve proper flush seating. Power down or de-energize any equipment before fastener replacement on electrical or mechanical assemblies. Avoid over-torquing, as alloy steel screws in small diameters can be susceptible to thread stripping in softer base materials.