Value Collection 307221BR Hex Socket Cap Screw 7/8-9

Product Description

The VALUE COLLECTION 307221BR is a hex socket cap screw designed for high-strength fastening applications in mechanical assemblies, industrial equipment, and structural connections. It features a 7/8-9 UNC thread size with a 6-1/2 inch length under head and is partially threaded, allowing for precise clamping force in bolted joints. The 9/16 inch hex drive socket accommodates standard hex keys and socket drive tools. Manufactured from alloy steel with a black oxide coating, this fastener meets ASTM A574 standards for mechanical properties. It is installed by machinists, millwrights, maintenance technicians, and mechanical contractors working on industrial and commercial equipment.

This screw is suited for heavy-duty bolted connections where a recessed hex drive is preferred over an external hex head. Partial threading allows the unthreaded shank to bear shear loads while the threaded section engages the mating nut or tapped hole. Common applications include machinery frames, hydraulic equipment mounts, structural brackets, and precision assemblies requiring controlled fastener engagement. The black oxide finish provides moderate corrosion resistance and reduces light reflection in close-tolerance assemblies.

Key Features

• 7/8-9 UNC thread size for heavy load-bearing fastening
• 6-1/2 inch length under head accommodates thick material stacks
• Partially threaded shank supports shear load transfer
• 9/16 inch hex socket drive for standard hex key or socket wrench installation
• Alloy steel construction meets ASTM A574 mechanical requirements
• Black oxide coating provides corrosion resistance and a low-reflectance finish

Compatibility

Designed as a standard ASTM A574 hex socket cap screw for use in tapped holes or with matching 7/8-9 UNC hex nuts in industrial and mechanical assembly applications.

Installation Notes

Installation is performed by qualified machinists, millwrights, or mechanical technicians. Ensure the mating tapped hole or nut matches the 7/8-9 UNC thread specification before installation. Use a 9/16 inch hex key or socket drive tool and follow ASME or equipment manufacturer torque specifications for the fastener grade and joint material. Inspect threads for damage and apply appropriate thread lubricant or anti-seize compound as required by the application.