Value Collection 99221 Hex Head Cap Screw 1-8x4 Grade 8

Product Description

The VALUE COLLECTION 99221 is a Grade 8 steel hex head cap screw in a 1-8 x 4 inch configuration, sold in a pack of 10. Manufactured to ASME B18.2.1 standards, this fastener features a Unified National Coarse (UNC) thread form and a partially threaded shank, leaving a smooth bearing surface beneath the head. Grade 8 designation indicates a high-strength carbon steel alloy suitable for demanding structural and mechanical assemblies. The uncoated finish means no plating or treatment is applied, making these appropriate for applications where coating compatibility or dimensional precision over the full fastener surface is required.

These cap screws are used in heavy-duty bolted connections across industrial, mechanical, and equipment assembly applications. The 4 inch length under head suits thicker material stacks or flanged joints where a shorter fastener would not achieve full engagement. Partial threading allows the smooth shank to bear shear loads in close-tolerance bores. Machinists, millwrights, and general maintenance technicians commonly install Grade 8 hex cap screws in structural steel connections, machinery frames, and equipment mounting applications.

Key Features

• Grade 8 high-strength steel construction for demanding fastening applications
• Partially threaded shank supports shear load bearing in close-tolerance bores
• UNC thread form for broad compatibility with standard inch-series nuts and tapped holes
• Meets ASME B18.2.1 dimensional standards for hex head cap screws
• Uncoated finish — no plating applied, suitable where coating-free surfaces are required
• Sold in a pack of 10 for job-lot use

Compatibility

Designed for use with standard inch-series Grade 8 or heavy hex nuts and tapped holes conforming to UNC thread standards in 1-8 thread pitch.

Installation Notes

Installation is typically performed by millwrights, maintenance technicians, or mechanical assemblers using a hex wrench or impact driver sized to the fastener head. Always ensure the mating nut or tapped hole is rated to the same Grade 8 specification to maintain joint integrity. Clean and inspect thread engagement before final torquing. Power down and de-energize any equipment before performing fastener replacement or maintenance on live machinery.