Holo-krome 72146 Hex Socket Cap Screw 5/16-18 Unc

Product Description

The HOLO-KROME 72146 is a hex socket cap screw designed for high-strength fastening applications in industrial, mechanical, and trade assembly work. It features a 5/16-18 UNC thread with a 3-1/4 inch length under head and is driven by a 1/4 inch hex socket. Constructed from alloy steel with a black oxide finish, this fastener delivers corrosion resistance and surface hardness suited to demanding environments. The screw is partially threaded, which provides a bearing surface useful in applications requiring controlled clamp load. It conforms to ASME B18.3 and ASTM A574 standards, making it appropriate for precision mechanical assemblies and structural fastening work.

This socket cap screw is used across a broad range of industrial and mechanical applications including HVAC equipment assemblies, pump and motor mounting, fabricated steel structures, and general machine maintenance. Its partially threaded shank makes it a common choice where fasteners pass through a clearance hole before threading into a tapped hole. Installers in mechanical, electrical, and plumbing trades use socket cap screws like this when access space limits wrench swing and a hex key or driver bit is required.

Key Features

• 5/16-18 UNC thread size for standard inch-series tapped holes
• 3-1/4 inch length under head with partial threading for clearance-hole applications
• 1/4 inch hex drive for use with standard hex keys or socket drivers
• Alloy steel construction meets ASTM A574 high-strength requirements
• Black oxide finish provides mild corrosion resistance and reduces light reflection
• Conforms to ASME B18.3 dimensional standards

Compatibility

Designed as an OEM-style replacement or standard-service hex socket cap screw for any application requiring a 5/16-18 UNC partially threaded fastener conforming to ASME B18.3 and ASTM A574.

Installation Notes

Installation should be performed by qualified mechanical or trade professionals familiar with fastener torque requirements for the specific joint material and application. Power down and de-energize any equipment before disassembling fastened assemblies. Use a properly sized 1/4 inch hex key or socket driver to avoid rounding the drive recess. Verify tapped hole depth and thread condition before installation to ensure full thread engagement.