Holo-krome 72420 Hex Socket Cap Screw 1-1/4-7 Unc 9 in

Product Description

The HOLO-KROME 72420 is a hex socket cap screw designed for high-strength fastening in demanding industrial and mechanical applications. It features a 1-1/4-7 UNC thread size with a 9-inch length under head and is partially threaded. The 7/8-inch hex drive accepts a standard hex key or Allen wrench for controlled torque application. Constructed from alloy steel with a black oxide finish, this screw provides solid mechanical strength and moderate corrosion resistance in dry or lightly oiled environments. It meets ASME B18.3 and ASTM A574 standards, confirming its suitability for structural and precision fastening work.

This fastener is suited for heavy-duty assemblies where high clamp load and precise fitment are required. The partial threading allows for shank engagement across thick material sections, making it appropriate for machinery mounting, structural steel connections, and equipment fabrication. Mechanical contractors, millwrights, and maintenance technicians working on industrial equipment will encounter this screw size in press frames, conveyor systems, and heavy structural assemblies. The black oxide coating is compatible with oil-based rust inhibitors for added protection in shop environments.

Key Features

• 1-1/4-7 UNC thread form for heavy-load fastening applications
• 9-inch length under head with partial threading for shank bearing in thick material
• 7/8-inch internal hex drive for high-torque installation with standard hex tooling
• Alloy steel construction meets ASTM A574 mechanical requirements
• Black oxide finish provides mild corrosion resistance and reduces light reflection
• Conforms to ASME B18.3 dimensional standards for socket cap screws

Compatibility

Designed as a standard ASME B18.3 hex socket cap screw for use in tapped holes or with compatible hex nuts in heavy industrial and mechanical assemblies requiring 1-1/4-7 UNC thread engagement.

Installation Notes

Installation should be performed by a qualified millwright, maintenance mechanic, or mechanical contractor using a properly sized 7/8-inch hex key or drive tool. De-energize and lock out all equipment before fastener installation or removal per applicable OSHA lockout/tagout procedures. Apply a thread lubricant or anti-seize compound as required by the assembly specification to achieve accurate torque readings. Inspect the tapped hole for damage or debris before installation to avoid cross-threading.