Holo-krome 72356 Hex Socket Cap Screw 7/8-9 Unc Alloy Steel

Product Description

The HOLO-KROME 72356 is a hex socket cap screw designed for high-strength fastening applications in mechanical assemblies, machinery, and industrial equipment. It features a 7/8-9 UNC thread and a 5-inch length under head, with a 3/4-inch hex drive that accepts standard hex keys and drive tools. The screw is partially threaded, which helps maintain clamping force in thicker assemblies. Constructed from alloy steel with a black oxide finish, it offers solid mechanical strength and moderate corrosion resistance in dry or lightly protected environments. This fastener meets ASME B18.3 and ASTM A574 standards, confirming compliance with recognized dimensional and mechanical property specifications.

This cap screw is suited for use in industrial machinery, structural fixtures, tooling, and equipment maintenance where a recessed hex drive is preferred over an external hex head. The 7/8-9 UNC coarse thread makes it well suited for general steel and iron assemblies where fast engagement and reliable clamping are priorities. It is commonly installed by millwrights, maintenance mechanics, and fabricators working on moderate to heavy-duty bolted connections. The black oxide finish helps the fastener blend into finished assemblies and provides light surface protection.

Key Features

• 7/8-9 UNC coarse thread for reliable engagement in steel and iron assemblies
• 5-inch length under head accommodates thicker structural or mechanical connections
• 3/4-inch hex socket drive for use with standard hex keys or socket drive tools
• Partially threaded shank maintains clamping load in bolted joint applications
• Alloy steel construction meets ASTM A574 mechanical property requirements
• Black oxide finish provides light corrosion resistance and a low-reflectance appearance

Compatibility

Designed as an OEM-style and aftermarket replacement hex socket cap screw for industrial machinery, fabricated steel assemblies, and mechanical equipment requiring a 7/8-9 UNC partially threaded fastener conforming to ASME B18.3.

Installation Notes

Installation should be performed by a qualified mechanic or maintenance technician using a properly sized 3/4-inch hex key or socket drive tool. Ensure mating threads are clean and free of debris before installation. Apply thread lubricant or anti-seize compound as required by the application to achieve accurate torque values. Always follow the applicable equipment manufacturer torque specifications and relevant industry standards when torquing alloy steel fasteners.