Value Collection 581125PR Hex Socket Cap Screw 4-40 Unc

Product Description

The VALUE COLLECTION 581125PR is a hex socket cap screw designed for precision fastening in mechanical assemblies, fixtures, and equipment where a low-profile, high-strength fastener is required. It features a 4-40 UNC thread size with a 1-1/4-inch length under the head and is partially threaded for positive clamping force. The 3/32-inch hex drive requires an Allen key or hex bit driver for installation. Constructed from alloy steel with a black oxide coating, this screw delivers corrosion resistance and surface hardness suited to demanding shop and field environments. It meets ASME/ANSI B18.3 and ASTM A574 standards.

This screw is commonly used in light mechanical assemblies, instrumentation panels, machine guards, and precision equipment where a socket-drive cap screw is specified. The 4-40 UNC thread is a fine, small-diameter thread typical in tight-clearance applications across electronics, HVAC controls, and light-duty structural fastening. The black oxide finish makes it a practical choice where minimal light reflection or low-level corrosion resistance is needed without adding significant dimensional thickness from plating.

Key Features

• 4-40 UNC thread size for fine-thread, small-diameter fastening applications
• 1-1/4-inch length under head with partial threading for positive clamp load
• 3/32-inch hex socket drive for Allen key or hex bit installation
• Alloy steel construction meets ASTM A574 mechanical requirements
• Black oxide coating provides mild corrosion resistance and low-glare finish
• Conforms to ASME/ANSI B18.3 dimensional standards

Compatibility

Designed as a standard ASME/ANSI B18.3 hex socket cap screw for use in any application specifying a 4-40 UNC, 1-1/4-inch alloy steel socket head cap screw with a 3/32-inch drive.

Installation Notes

Installation is performed with a 3/32-inch hex key or hex bit driver torqued to the fastener specification for the assembly being serviced. Ensure the mating threaded hole is clean and free of debris before driving. Do not exceed the rated seating torque for 4-40 alloy steel fasteners, as the small thread form is susceptible to galling and cross-threading. Where applicable, follow equipment manufacturer torque specifications and relevant ASME or industry assembly standards.