Value Collection 721278BR Flat Socket Cap Screw 5/8-18

Product Description

The VALUE COLLECTION 721278BR is a flat socket cap screw designed for flush or countersunk fastening applications in mechanical assemblies, fixtures, and structural components. It features a 82-degree flat head driven by a 3/8-inch hex socket, allowing the fastener to sit flush with or below the mating surface when installed in a properly countersunk hole. The screw measures 5/8-18 UNF thread by 2 inches in overall length and is fully threaded. Constructed from alloy steel with a black oxide finish, it provides solid mechanical strength along with basic corrosion resistance in dry or lightly oiled environments. This fastener is installed by machinists, millwrights, maintenance technicians, and assembly professionals.

This flat socket cap screw is suited for applications where a smooth, low-profile surface is required after fastening. Common uses include machine frames, jigs and fixtures, tooling plates, motor mounts, and general industrial assemblies where an Allen-key-driven countersunk fastener is preferred over a hex bolt or standard button-head cap screw. The fine UNF thread pitch makes it appropriate for applications requiring precise clamp load or where vibration resistance is a consideration.

Key Features

• 82-degree flat head profile seats flush in standard countersunk holes
• 3/8-inch hex socket drive for use with standard Allen or hex keys
• 5/8-18 UNF fine thread for precise engagement and vibration resistance
• Fully threaded 2-inch length maximizes thread engagement across the full shank
• Alloy steel construction meets ASME/ANSI B18.3 and ASTM F835 standards
• Black oxide finish provides a uniform appearance and light surface protection

Compatibility

Designed as a standard 5/8-18 UNF flat socket cap screw conforming to ASME/ANSI B18.3 and ASTM F835, suitable for use in any countersunk application requiring that thread size and drive type.

Installation Notes

Installation requires a 3/8-inch hex key or Allen driver. The mating hole must be countersunk to 82 degrees for proper head seating. Power down or de-energize any equipment before accessing fastener locations on machinery. Do not overtighten; torque to values specified in the applicable engineering drawings or assembly standards for 5/8-18 alloy steel fasteners.