Value Collection 581127PR Hex Socket Cap Screw 4-40 Unc

Product Description

The VALUE COLLECTION 581127PR is a hex socket cap screw designed for precision fastening in mechanical assemblies, tooling, and machine components. It features a 4-40 UNC thread size and a 1-3/8 inch length under the head, with partial threading along the shank. The 3/32 inch hex drive accepts a standard hex key or Allen wrench. The fastener body is made from alloy steel and finished with a black oxide coating, which provides mild corrosion resistance and reduces light reflection on exposed surfaces. Licensed machinists, millwrights, and maintenance technicians typically specify this type of fastener for close-tolerance work where a clean recessed drive is required.

This fastener is suited for light-duty to medium-duty clamping and assembly applications where a low-profile socket head is preferred over an external hex. Common uses include fixture plates, jigs, small machine frames, electronics enclosures, and general industrial assembly work. The 4-40 UNC thread is a standard coarse-series designation appropriate for tapped holes in steel, aluminum, and engineered plastics. The partial threading allows for controlled clamping force across unthreaded shank sections.

Key Features

• 4-40 UNC thread for compatibility with standard tapped holes in small-format assemblies
• 1-3/8 inch length under head with partial threading for precise clamping engagement
• 3/32 inch hex socket drive accepts standard hex keys
• Alloy steel construction for strength in demanding fastening applications
• Black oxide finish provides mild corrosion resistance and a clean, non-reflective appearance
• Meets ASME/ANSI B18.3 and ASTM A574 standards for dimensional and mechanical compliance

Compatibility

Designed as an OEM-style replacement or standard-service fastener for any application requiring a 4-40 UNC hex socket cap screw with a 1-3/8 inch length under head and 3/32 inch drive.

Installation Notes

Installation requires a 3/32 inch hex key or ball-end driver. Ensure the mating tapped hole is clean and free of debris before installation. Do not over-torque small-diameter fasteners, as the 4-40 thread is susceptible to stripping in soft materials. Follow applicable ASME or facility torque guidelines for the specific material and joint configuration.