Holo-krome 72404 Hex Socket Cap Screw 1-1/4-7 Unc

Product Description

The HOLO-KROME 72404 is a hex socket cap screw designed for high-strength bolted connections in industrial, mechanical, and structural assemblies. It features a 1-1/4-7 UNC thread form, a 4-inch length under head, and a 7/8-inch hex drive socket. The fastener is machined from alloy steel and finished with a black oxide coating that provides mild corrosion resistance and a uniform dark appearance. Installation requires a 7/8-inch hex key or Allen-style driver. This screw is partially threaded, which supports clamping force distribution in thick-material applications. Licensed mechanics, millwrights, and industrial maintenance technicians are the primary installers.

This cap screw is suited for heavy-duty bolted joints in machinery frames, hydraulic components, tooling fixtures, and structural steel assemblies requiring high tensile strength. The 1-1/4-7 UNC coarse thread pattern is common in applications where quick engagement and resistance to cross-threading are priorities. The black oxide finish is appropriate for interior or low-moisture environments. It is sold individually, making it practical for single-unit repairs or low-volume maintenance work without requiring purchase of a full lot.

Key Features

• 1-1/4-7 UNC coarse thread for fast engagement in high-load joints
• 4-inch length under head suits thick-material or deep-clearance installations
• 7/8-inch hex socket drive compatible with standard Allen keys and hex bit drivers
• Alloy steel construction meets ASME B18.3 and ASTM A574 standards
• Black oxide coating provides surface protection and reduces light reflection
• Partial threading supports precise clamping and shear-load performance

Compatibility

Designed as a direct-fit replacement or service screw for applications requiring a 1-1/4-7 UNC hex socket cap screw conforming to ASME B18.3 and ASTM A574 specifications.

Installation Notes

Installation should be performed by a qualified mechanic or millwright using a calibrated torque wrench and the correct 7/8-inch hex key or drive bit. Ensure mating threads are clean and free of debris before installation, and verify that the tapped hole depth accommodates the partial thread length. Black oxide fasteners are not rated for outdoor or high-humidity environments without additional lubrication or topcoat protection. Always de-energize and lock out any equipment before replacing fasteners in live machinery per applicable OSHA lockout/tagout procedures.