Holo-krome 72344 Hex Socket Cap Screw 7/8-9 Unc Alloy Steel

Product Description

The HOLO-KROME 72344 is a hex socket cap screw designed for high-strength fastening applications in mechanical assemblies, industrial equipment, and structural connections. It features a 7/8-9 UNC thread and a 2-3/4 inch length under head, with full threading along the entire shank. The drive is a 3/4 inch internal hex socket, requiring an Allen or hex key for installation. Constructed from alloy steel with a black oxide coating, this fastener delivers strong tensile performance and moderate corrosion resistance. It is a standard choice for machinists, maintenance technicians, and industrial assembly professionals working to ASME B18.3 and ASTM A574 specifications.

This screw is suited for use in heavy equipment, machine frames, jigs, fixtures, and structural steel assemblies where a high-torque, recessed-drive fastener is required. The 7/8-9 UNC coarse thread provides reliable engagement in steel and iron tapped holes. Full threading along the body makes it appropriate for through-bolting applications or for use with a nut across the full grip length. It is commonly installed by millwrights, machinists, and maintenance mechanics in industrial and manufacturing environments.

Key Features

• 7/8-9 UNC coarse thread for reliable engagement in standard tapped steel and iron holes
• 2-3/4 inch length under head with full threading along the entire shank
• 3/4 inch internal hex socket drive for high-torque installation with an Allen key or hex driver
• Alloy steel construction meets ASTM A574 high-strength fastener requirements
• Black oxide finish provides mild corrosion resistance and reduces light reflection in service
• Manufactured to ASME B18.3 dimensional standards for consistent fit and interchangeability

Compatibility

Designed as an OEM-style replacement or direct-fit fastener for applications requiring a 7/8-9 UNC hex socket cap screw per ASME B18.3 and ASTM A574 standards.

Installation Notes

Installation is performed by machinists, millwrights, or maintenance mechanics using a 3/4 inch hex key or Allen driver. Ensure the tapped hole or nut is clean and free of debris before threading. De-energize and lock out all equipment before installing or removing fasteners in powered machinery. Do not substitute a mismatched drive size, as rounding the socket will damage the fastener head and complicate removal.