Value Collection 581598PR Hex Socket Cap Screw 1/2-20 Unf

Product Description

The VALUE COLLECTION 581598PR is a partially threaded hex socket cap screw designed for high-strength fastening applications in mechanical, structural, and industrial assemblies. Manufactured from alloy steel with a black oxide finish, this fastener provides corrosion resistance and reduced light reflection in service environments. It features a 1/2-20 UNF thread size, a 6-inch length under head, and a 3/8-inch hex socket drive. The black oxide coating also helps retain lubrication applied during installation. This screw meets ASME/ANSI B18.3 and ASTM A574 standards, making it appropriate for precision and high-load fastening work performed by mechanical contractors, millwrights, and maintenance technicians.

This cap screw is suited for use in general industrial machinery, equipment assembly, tooling fixtures, and structural components where fine thread engagement and high clamp load are required. The 1/2-20 UNF thread pitch offers greater thread engagement and vibration resistance compared to coarse thread equivalents, making it a common choice in applications subject to dynamic loading or controlled torque requirements.

Key Features

• 1/2-20 UNF fine thread for high clamp load and vibration resistance
• 6-inch length under head for deep fastening applications
• 3/8-inch hex socket drive for use with standard Allen or hex bit drivers
• Alloy steel construction meets ASTM A574 high-strength requirements
• Black oxide finish provides mild corrosion resistance and reduces galling
• Partially threaded shank for shear-load bearing and precise alignment
• Meets ASME/ANSI B18.3 dimensional standards

Compatibility

Designed as a standard ASME/ANSI B18.3 hex socket cap screw suitable for use in machinery, fixtures, and assemblies requiring a 1/2-20 UNF partially threaded fastener.

Installation Notes

Installation should be performed by a qualified mechanic or technician using a calibrated torque wrench and the appropriate 3/8-inch hex key or bit. Clean and inspect the threaded bore before installation to ensure proper thread engagement. Apply an appropriate thread lubricant or anti-seize compound as required by the assembly specification. Never exceed the rated torque for the fastener grade or the base material being threaded into.