Holo-krome 73144 Hex Socket Cap Screw 1/2-20 Unf Alloy Steel

Product Description

The HOLO-KROME 73144 is a hex socket cap screw engineered for high-strength fastening applications in mechanical assemblies, industrial equipment, and trade installations. It features a 1/2-20 UNF thread size with a 3-inch length under head and partial threading. The drive is a 3/8-inch internal hex socket, requiring a hex key or Allen driver for installation and removal. Constructed from alloy steel with a black oxide finish, this screw delivers solid tensile strength and moderate corrosion resistance in protected environments. It conforms to ASME B18.3 and ASTM A574 standards, making it a recognized choice where specification compliance is required.

This screw is suited for mechanical, HVAC equipment mounting, pump and motor assemblies, and structural fastening tasks where a flush or low-profile cap head is needed. The 1/2-20 UNF fine thread pitch provides strong clamping force and reduced tendency to loosen under vibration. Partially threaded shanks allow precise clamping without thread engagement through the full grip length, which is preferred in multi-layer assemblies and close-tolerance joints. Licensed mechanics, millwrights, and trade technicians working on equipment maintenance or new installation will encounter this fastener type regularly.

Key Features

• 1/2-20 UNF fine thread for high clamping force and vibration resistance
• 3 inches length under head with partial threading for controlled grip-length clamping
• 3/8-inch hex socket drive compatible with standard Allen keys and hex bit drivers
• Alloy steel construction meets ASTM A574 mechanical property requirements
• Black oxide finish provides mild corrosion protection and reduced light reflection
• Conforms to ASME B18.3 dimensional standard

Compatibility

Designed as a standard ASME B18.3 hex socket cap screw for use in any application requiring a 1/2-20 UNF partially threaded fastener with a 3-inch length under head.

Installation Notes

Installation and removal require a properly sized hex key or hex bit driver; using an undersized or worn driver can strip the socket. Torque to the assembly specification provided by the equipment manufacturer. Ensure mating threads are clean and free of debris before installation. Always follow applicable mechanical codes and equipment service procedures when fastening structural or pressure-bearing components.