Value Collection 581121PR Hex Socket Cap Screw 4-40 Unc

Product Description

The VALUE COLLECTION 581121PR is a hex socket cap screw designed for precision fastening in mechanical assemblies, tooling fixtures, and machine components. It carries a 4-40 UNC thread and measures 7/8 inches in length under the head, making it suited for compact, close-tolerance applications. Drive is a 3/32-inch hex socket, allowing engagement with an Allen wrench or hex bit driver. The fastener is manufactured from alloy steel and finished with a black oxide coating that provides mild corrosion resistance and reduces light reflection. It is fully threaded along its entire shaft length. This type of fastener is commonly installed by machinists, maintenance technicians, and mechanical assemblers in both production and field settings.

This screw is appropriate for light-duty to medium-duty clamping and assembly applications where a low-profile socket head is required and clearance for a standard hex or Phillips driver is limited. Fully threaded construction allows engagement along the complete shaft, which is useful in thin-material or through-bolt configurations. Black oxide finish suits indoor mechanical environments and applications where a non-reflective surface finish is specified.

Key Features

• 4-40 UNC thread for fine-pitch, small-diameter fastening applications
• 7/8-inch length under head for compact assembly fitment
• 3/32-inch hex socket drive for engagement with standard Allen wrenches and hex bit drivers
• Fully threaded shaft for maximum thread engagement in thin materials
• Alloy steel construction for strength in mechanical and tooling applications
• Black oxide finish for mild corrosion resistance and reduced light reflection

Compatibility

Designed as an OEM-style and general-purpose replacement or supplemental fastener for mechanical assemblies, fixtures, and equipment requiring 4-40 UNC socket cap screws with a 7/8-inch under-head length.

Installation Notes

Installation is performed with a 3/32-inch hex key or Allen driver; ensure the driver is fully seated before applying torque to avoid rounding the socket. Thread the fastener into clean, properly tapped holes to maintain thread integrity and accurate clamping force. Follow applicable ASME and ASTM guidelines for fastener installation procedures. Minimum order quantity for this item is 100 pieces.