Value Collection -33721-2 Hex Socket Cap Screw 1-1/4-7 Unc

Product Description

The VALUE COLLECTION -33721-2 is a hex socket cap screw designed for high-strength bolted assemblies in industrial, mechanical, and structural applications. Manufactured from alloy steel with a black oxide finish, this fastener meets ASME/ANSI B18.3 and ASTM A574 standards, confirming it is engineered to handle demanding torque and load requirements. The 1-1/4-7 UNC thread size and 4-inch length under head make it suited for thick-stock clamping situations. Drive engagement is via a 7/8-inch hex socket, compatible with standard socket drive tooling. Threading is partial, meaning the unthreaded shank provides a precise shear-load bearing surface commonly required in close-tolerance joint designs.

This cap screw is used across a wide range of industrial environments including heavy equipment assembly, machine tool fabrication, structural steel connections, and maintenance repair operations. The partially threaded configuration is a deliberate design choice in applications where the bolt shank must bear lateral shear loads without relying on thread engagement in the joint interface. It is installed by machinists, millwrights, and maintenance technicians wherever high-strength UNC fasteners are required.

Key Features

• Thread size 1-1/4-7 UNC for heavy-duty clamping applications
• 4-inch length under head accommodates thick-stock assemblies
• Partially threaded shank provides shear-load bearing surface
• 7/8-inch hex socket drive for positive torque transfer
• Alloy steel construction meets ASTM A574 mechanical property requirements
• Black oxide finish provides mild corrosion resistance and reduces light reflection in machined assemblies

Compatibility

Designed as an OEM-style and MRO replacement hex socket cap screw for industrial assemblies requiring 1-1/4-7 UNC partially threaded fasteners conforming to ASME/ANSI B18.3 and ASTM A574 standards.

Installation Notes

Installation should be performed by a qualified mechanic or millwright using a calibrated torque wrench and the appropriate 7/8-inch hex socket. Always clean and inspect threaded holes before installation and ensure thread engagement depth meets engineering specifications for the joint. Apply thread lubricant or anti-seize only if specified by the assembly drawing, as lubrication significantly affects torque-to-clamp-force relationships. De-energize and lock out all equipment before performing any fastener service on machinery.