Value Collection 581551PR Hex Socket Cap Screw 1/2-13 Unc

Product Description

The VALUE COLLECTION 581551PR is a partially threaded hex socket cap screw designed for high-strength fastening in industrial, mechanical, and structural applications. It features a 1/2-13 UNC thread size and measures 4.25 inches in length under the head. Driven with a 3/8-inch hex key, this screw is manufactured from alloy steel and finished with a black oxide coating that provides mild corrosion resistance and a low-reflectance appearance. Licensed trades and maintenance professionals use this fastener wherever tensile strength and consistent clamping load are critical.

This screw is suited for machine assembly, tooling fixtures, heavy equipment maintenance, and general industrial fabrication where socket-head fasteners are specified. The 1/2-13 UNC coarse thread engages quickly and resists cross-threading in typical shop and field conditions. The partial threading allows the unthreaded shank to function as a shoulder, which helps align mating components. It meets ASME/ANSI B18.3 and ASTM A574 dimensional and mechanical property standards, making it appropriate for engineered assemblies that call out those specifications.

Key Features

• 1/2-13 UNC coarse thread for fast engagement and broad compatibility with standard tapped holes
• 4.25-inch length under head with partial threading, providing an unthreaded shank for component alignment
• 3/8-inch hex drive for use with standard Allen keys and hex bit drivers
• Alloy steel construction rated to ASTM A574 mechanical property requirements
• Black oxide finish for mild corrosion resistance and reduced surface reflectance
• Meets ASME/ANSI B18.3 dimensional standards for consistent fit across machined applications

Compatibility

Designed as an OEM-style or aftermarket replacement fastener for any application requiring a 1/2-13 UNC partially threaded socket head cap screw conforming to ASME/ANSI B18.3 and ASTM A574 standards.

Installation Notes

Installation is performed by machinists, millwrights, maintenance technicians, or other qualified tradespeople using a 3/8-inch hex key or socket bit. Always verify the tapped hole thread class and depth before installation. De-energize, depressurize, or otherwise make safe any equipment before replacing fasteners on live assemblies. Do not substitute a fastener of lower grade when an ASTM A574 alloy steel screw is specified by the design.