Value Collection 581129PR Hex Socket Cap Screw 4-40 Unc

Product Description

The VALUE COLLECTION 581129PR is a hex socket cap screw designed for precision fastening in mechanical assemblies and close-tolerance applications. It features a 4-40 UNC thread size with a 1-1/2 inch length under head and a 3/32 inch hex drive socket. Constructed from alloy steel with a black oxide finish, the screw delivers solid tensile strength while the coating provides moderate corrosion resistance and reduces light reflection. The partially threaded shank allows for clamping force between mating components. This fastener meets ASME/ANSI B18.3 and ASTM A574 standards, making it appropriate for applications where dimensional and mechanical conformance is required.

This screw is suited for light-duty precision assemblies, instrument panels, electronics enclosures, and mechanical fixtures where a low-profile socket drive is preferred over a hex head. The 4-40 UNC thread is common in small-scale mechanical work and is regularly specified in OEM equipment, tooling fixtures, and field service repairs across industrial, electrical, and HVAC applications. A licensed technician or machinist familiar with small fastener installation will find this screw a standard fit for many routine and specialized tasks.

Key Features

• 4-40 UNC thread size for compatibility with standard tapped holes in small assemblies
• 1-1/2 inch length under head with partial threading for controlled clamping
• 3/32 inch hex socket drive for use with standard Allen wrenches and hex keys
• Alloy steel construction meets ASTM A574 mechanical requirements
• Black oxide coating reduces surface corrosion and minimizes glare
• Conforms to ASME/ANSI B18.3 dimensional standards

Compatibility

Designed as a standard 4-40 UNC hex socket cap screw for use in any tapped hole conforming to 4-40 UNC thread specifications per ASME/ANSI B18.3.

Installation Notes

Install with a calibrated hex key or Allen driver sized at 3/32 inch to avoid rounding the socket. Ensure the tapped hole is clean and free of debris before threading. Do not exceed the rated torque for 4-40 alloy steel fasteners as specified in applicable machinery or equipment documentation. Black oxide finish is not a heavy-duty corrosion barrier; use appropriate thread-locking compound or sealant if the installation environment involves moisture exposure.