Value Collection 581586PS Hex Socket Cap Screw 1/2-20 Unf

Product Description

The VALUE COLLECTION 581586PS is a hex socket cap screw designed for high-strength fastening applications in mechanical assemblies, tooling fixtures, and industrial equipment. It features a 1/2-20 UNF thread and a 3-1/4 inch length under head, with a 3/8 inch hex drive socket. Manufactured from alloy steel with a black oxide finish, this fastener meets the dimensional and mechanical requirements of ASME/ANSI B18.3 and ASTM A574. The black oxide coating provides moderate corrosion resistance and reduces light reflection in precision applications. It is partially threaded, which is standard for grip-length fasteners used where clamp load and shank shear strength both matter.

This cap screw suits applications across industrial maintenance, machine building, die and mold work, hydraulic assemblies, and general mechanical fabrication. The 1/2-20 UNF fine thread pitch offers tighter thread engagement and greater tensile strength compared to coarse thread equivalents, making it a common choice in high-vibration environments. Machinists, millwrights, maintenance technicians, and field service mechanics install this style of fastener wherever a recessed hex drive and high clamping force are required. Sold individually, with a minimum order quantity of 5 units.

Key Features

• 1/2-20 UNF fine thread for high clamping load and vibration resistance
• 3-1/4 inch length under head with partial threading for shank grip strength
• 3/8 inch hex socket drive for standard Allen key or hex bit tooling
• Alloy steel construction meeting ASTM A574 mechanical requirements
• Black oxide finish for surface protection and reduced surface reflectivity
• Conforms to ASME/ANSI B18.3 dimensional standards

Compatibility

Designed as a standard ASME/ANSI B18.3 hex socket cap screw for use in any 1/2-20 UNF tapped hole requiring a partially threaded alloy steel fastener.

Installation Notes

Installation requires a 3/8 inch hex key or socket bit driver; confirm the tapped hole thread form is 1/2-20 UNF before driving. Torque to the value specified in the applicable engineering documentation for the assembly — do not exceed the rated fastener capacity. Always de-energize, depressurize, or lock out the assembly before removing or replacing structural fasteners per applicable OSHA lockout/tagout procedures. Inspect threads for contamination or damage before installation.