Value Collection 721164PR Flat Socket Cap Screw 5/16-18

Product Description

The VALUE COLLECTION 721164PR is a flat socket cap screw designed for flush or countersunk fastening applications in metal assemblies. Featuring an 82-degree flat head profile and a 3/16-inch hex socket drive, this screw seats below the surface to eliminate protrusions that could interfere with mating parts or movement. The 5/16-18 UNC thread is fully threaded along the 3/8-inch overall length, providing consistent clamp load from head to tip. Manufactured from alloy steel with a black oxide finish, it offers solid mechanical strength and moderate corrosion resistance in dry or lightly oiled environments. Licensed tradespeople and machine shop technicians use this fastener in structural, mechanical, and equipment assemblies.

This fastener is suited for countersunk hole applications in metal fabrication, machinery, jigs, fixtures, and equipment panels. The 82-degree flat head angle is the standard for inch-series countersunk fasteners per ASME/ANSI B18.3, making it compatible with standard countersink tooling. It is commonly used in applications where a flush surface finish is required and where an alloy steel fastener provides adequate tensile strength. The black oxide finish blends with dark or unfinished steel surfaces and provides light lubricity to aid installation.

Key Features

• 82-degree flat head profile for flush, countersunk installation
• 3/16-inch hex socket drive for use with standard hex keys or socket drivers
• Fully threaded 5/16-18 UNC along the full 3/8-inch overall length
• Alloy steel construction for high tensile and shear strength
• Black oxide finish provides light corrosion resistance and reduced light reflection
• Conforms to ASME/ANSI B18.3 and ASTM F835 fastener standards

Compatibility

Designed as a standard inch-series flat socket cap screw per ASME/ANSI B18.3, compatible with any application requiring a 5/16-18 UNC countersunk fastener with an 82-degree seat angle and hex socket drive.

Installation Notes

Installation requires a properly prepared 82-degree countersink in the mating material to achieve full head seating and correct clamp load. Use a calibrated hex key or T-handle driver sized to 3/16 inch to avoid rounding the socket. De-energize or lock out any equipment before fastener replacement in live assemblies. Alloy steel fasteners in black oxide finish should not be used as the sole corrosion barrier in wet or outdoor environments without additional protective treatment.