Holo-krome 72406 Hex Socket Cap Screw 1-1/4-7 Unc

Product Description

The HOLO-KROME 72406 is a heavy-duty hex socket cap screw designed for high-strength fastening applications in industrial, mechanical, and structural assemblies. Manufactured from alloy steel with a black oxide coating, this fastener delivers corrosion resistance and a clean, low-reflectance finish suited to demanding service environments. The screw uses a 7/8-inch internal hex drive and features a 1-1/4-7 UNC thread with 4-1/2 inches of length under the head. It is partially threaded, making it well suited for clamping applications where full thread engagement through the joint is not required. Meets ASME B18.3 and ASTM A574 standards. Licensed tradespeople and maintenance machinists are the typical installers.

This fastener is used across a wide range of industrial and mechanical applications including heavy equipment assembly, structural steel connections, jig and fixture work, pump and compressor mounting, and other high-load bolted joints. The 1-1/4-7 UNC thread is a coarse-thread series well matched to tapped holes in steel and iron components. The black oxide finish is appropriate for interior or sheltered exterior environments where moderate corrosion protection is needed alongside dimensional consistency.

Key Features

• 1-1/4-7 UNC coarse thread for reliable engagement in steel and cast iron tapped bores
• 4-1/2 inch length under head with partial threading for clamping-style joint applications
• 7/8-inch hex socket drive compatible with standard hex keys and impact tooling
• Alloy steel construction meets ASTM A574 high-strength fastener requirements
• Black oxide coating provides corrosion resistance and reduces light reflection
• Conforms to ASME B18.3 dimensional standards for socket head cap screws

Compatibility

Designed as an OEM-style and aftermarket replacement hex socket cap screw for industrial equipment and mechanical assemblies requiring a 1-1/4-7 UNC partially threaded fastener per ASME B18.3 and ASTM A574.

Installation Notes

Installation should be performed by a qualified machinist or maintenance technician familiar with high-strength fastener procedures. De-energize and lock out any equipment before disassembling bolted joints. Use a calibrated torque wrench and a properly sized 7/8-inch hex key or socket to avoid drive socket damage. Follow applicable industry torque specifications for ASTM A574 alloy steel cap screws based on joint design - do not estimate torque by feel on high-load connections.