Value Collection 451059PR Hex Head Cap Screw 1/4-28 X 8 in Grade 8

Product Description

The VALUE COLLECTION 451059PR is a Grade 8 steel hex head cap screw with a 1/4-28 UNF thread and an 8-inch length under head. Partially threaded, it is designed for high-strength fastening applications where a smooth shank provides shear resistance and precise clamping. The bright, uncoated finish leaves the bare steel surface exposed, making it suitable for environments where coating interference with dimensional tolerances is a concern or where a secondary finish will be applied. Manufactured to ASME B18.2.1 standards, this fastener delivers consistent dimensional accuracy across the thread form, head geometry, and overall length. Installation requires a 7/16-inch hex key or socket driver.

This cap screw is appropriate for mechanical assemblies, fabrication work, and maintenance applications requiring a fine-thread, high-strength fastener. The 1/4-28 UNF thread provides finer pitch than its coarse-thread counterpart, offering improved tensile strength and better resistance to loosening under vibration. It is commonly used in automotive, industrial machinery, and general metalworking applications where Grade 8 strength and precise thread engagement are required. The partial thread design is particularly useful when the fastener must clamp two or more components with an unthreaded bearing surface along part of the shank.

Key Features

• Grade 8 steel construction for high tensile and proof load strength
• 1/4-28 UNF fine thread for improved vibration resistance and clamping force
• Partially threaded shank provides a smooth bearing surface for shear-load applications
• Bright uncoated finish maintains precise dimensional tolerances
• Conforms to ASME B18.2.1 for consistent head and thread dimensions
• 7/16-inch hex drive for standard socket or wrench installation

Compatibility

Designed as an OEM-style replacement or standard-service fastener for mechanical assemblies requiring a 1/4-28 UNF Grade 8 partially threaded hex head cap screw per ASME B18.2.1.

Installation Notes

Installation is performed by mechanical maintenance technicians and machinists using a 7/16-inch socket, wrench, or hex driver. Always de-energize, depressurize, or otherwise isolate the assembly before disassembling or replacing fasteners. Grade 8 fasteners should be installed with appropriate thread lubrication or anti-seize where required by the application to achieve accurate clamp load. Do not substitute a lower-grade fastener in any application specifying Grade 8 hardware.