Value Collection 581590PR Hex Socket Cap Screw 1/2-20 Unf

Product Description

The VALUE COLLECTION 581590PR is a partially threaded hex socket cap screw designed for high-strength fastening applications where a flush or recessed head profile is required. It features a 1/2-20 UNF thread size and measures 4 inches under the head. Driven with a 3/8-inch hex key, the screw is manufactured from alloy steel and finished with a black oxide coating that provides moderate corrosion resistance and reduces light reflection. This fastener meets ASME/ANSI B18.3 and ASTM A574 standards, confirming its suitability for demanding mechanical and structural assemblies.

This socket cap screw is used across a wide range of industrial, mechanical, and maintenance applications. Typical installations include machine guards, fixture plates, hydraulic components, and equipment housings where a recessed drive fastener is preferred over a hex head. The 1/2-20 UNF fine thread pitch provides strong clamping force and precise torque control, making it a common choice in precision assemblies and retrofit work. Machinists, millwrights, and maintenance technicians regularly use this fastener in both OEM and field-service settings.

Key Features

• 1/2-20 UNF fine thread for high clamping force and precise torque control
• 4-inch length under head accommodates medium to deep material stacks
• Partially threaded shank provides a bearing surface for shear load resistance
• Alloy steel construction meets ASTM A574 high-strength requirements
• Black oxide finish reduces surface reflectivity and offers mild corrosion protection
• 3/8-inch hex drive compatible with standard hex keys and socket drive tools

Compatibility

Designed as an OEM-style replacement or standard-service fastener for any application requiring a 1/2-20 UNF partially threaded hex socket cap screw conforming to ASME/ANSI B18.3 and ASTM A574.

Installation Notes

Installation is performed with a 3/8-inch hex key or Allen-drive socket. Ensure the mating threaded hole is clean and free of debris before driving. Power down and de-energize any equipment before accessing fastened assemblies on live machinery. Follow applicable torque specifications from the equipment manufacturer or engineering drawings, as no product-specific torque value is published with this fastener.