Value Collection 721009PR Flat Socket Cap Screw 1/2-20

Product Description

The VALUE COLLECTION 721009PR is a flat socket cap screw designed for flush or countersunk fastening applications in metal assemblies and structural components. It features an 82-degree flat head with a 5/16-inch hex socket drive, allowing installation with a standard hex key or Allen driver. The screw is partially threaded along a 4-inch overall length with a 1/2-20 UNF thread size, providing fine-thread engagement suitable for applications requiring precise clamping force. Manufactured from alloy steel with a black oxide finish, it offers increased hardness and moderate corrosion resistance. Machinists, millwrights, and mechanical contractors typically install this fastener in fabricated steel structures, machinery frames, and equipment enclosures.

This flat socket cap screw is suited for industrial, commercial, and OEM manufacturing applications where a low-profile, flush-mount fastener is required. The 82-degree countersunk head conforms to ASME/ANSI B18.3 and ASTM F835 standards, making it appropriate for controlled-fit assemblies in mechanical systems. Partial threading provides an unthreaded shank section that can serve as a shoulder or alignment feature within bored holes. The fine UNF thread pitch makes it well-suited for thin-walled materials or applications where vibration resistance and precise torque control are priorities.

Key Features

• 82-degree flat countersunk head for flush installation in chamfered or countersunk holes
• 5/16-inch hex socket drive compatible with standard Allen keys and hex drivers
• 1/2-20 UNF fine-thread specification for precise torque control and vibration resistance
• Partially threaded shank allows use as a shoulder or alignment feature
• Alloy steel construction with black oxide finish for hardness and moderate corrosion resistance
• Meets ASME/ANSI B18.3 and ASTM F835 fastener standards

Compatibility

Designed as a standard-dimension replacement or OEM-style flat socket cap screw for machinery, fabricated steel assemblies, and mechanical equipment requiring a 1/2-20 UNF countersunk fastener conforming to ASME/ANSI B18.3 and ASTM F835.

Installation Notes

Installation is typically performed by machinists, millwrights, or maintenance technicians using a calibrated torque wrench and the appropriate 5/16-inch hex key or driver bit. Ensure the mating countersink angle matches 82 degrees before installation to achieve full head seating. De-energize and lock out any equipment before servicing fasteners in live mechanical assemblies, following applicable OSHA lockout/tagout procedures. Do not exceed the rated mechanical load for the fastener grade or substitute with non-alloy hardware in load-bearing applications.