Holo-krome 77544 Hex Socket Cap Screw 1/2-20 Unf

Product Description

The HOLO-KROME 77544 is a hex socket cap screw designed for high-strength mechanical fastening applications. It features a 1/2-20 UNF thread size with a 4.5-inch length under head and is partially threaded along the shank. The 3/8-inch hex drive allows for secure torquing with a standard hex key or Allen wrench. Manufactured from alloy steel with a black oxide finish, this screw delivers corrosion resistance and reduced light glare, making it suitable for demanding industrial and mechanical assembly work. Licensed trades and machine shops rely on this style of fastener for precision-critical connections.

This screw is appropriate for use in mechanical assemblies, fixtures, jigs, industrial equipment, and structural components where high clamping force and precise fit are required. The partially threaded shank provides a strong grip interface for load-bearing joints. The fine 20-threads-per-inch UNF pitch allows for tighter torque control compared to coarse-thread equivalents, making this screw well-suited for applications that experience vibration or where fine adjustment during installation is needed.

Key Features

• 1/2-20 UNF fine thread for precise torque control and vibration resistance
• 4.5-inch length under head accommodates thicker material stacks
• Partially threaded shank supports shear-load and alignment applications
• 3/8-inch hex socket drive for use with standard Allen keys or hex bit drivers
• Alloy steel construction provides high tensile strength
• Black oxide finish offers mild corrosion resistance and low-glare surface
• Manufactured to ASME B18.3 and ASTM A574 standards

Compatibility

Designed as an OEM-style replacement or standard-fit hex socket cap screw for mechanical assemblies requiring a 1/2-20 UNF thread, 4.5-inch length under head, and 3/8-inch hex drive, conforming to ASME B18.3 and ASTM A574 specifications.

Installation Notes

Installation is performed by machinists, millwrights, or mechanical assemblers using a 3/8-inch hex key or socket bit. Always ensure the mating threaded hole is clean and free of debris before installation. Do not exceed the rated torque range for the fastener grade and material combination in use. Follow applicable industry standards and equipment manufacturer guidelines for torque specifications and thread engagement depth.