Holo-krome 73143 Hex Socket Cap Screw 1/2-20 Unf Alloy Steel

Product Description

The HOLO-KROME 73143 is a hex socket cap screw designed for high-strength fastening applications where a recessed drive and clean seating surface are required. It features a 1/2-20 UNF thread, a 2.75 inches length under head, and a 3/8 inch hex socket drive. The screw is partially threaded and manufactured from alloy steel with a black oxide finish, providing corrosion resistance and a consistent surface hardness. It meets ASME B18.3 and ASTM A574 standards, making it appropriate for demanding mechanical assemblies. Typical installers include millwrights, pipefitters, HVAC technicians, and industrial maintenance personnel who require a precise, torque-capable fastener.

This cap screw suits applications in mechanical equipment, structural assemblies, and industrial machinery where a flush or semi-recessed fastener head is preferred. The 1/2-20 UNF fine thread pitch provides higher tensile strength and better resistance to loosening under vibration compared to coarse thread equivalents. The black oxide finish is suitable for indoor and light-duty outdoor environments. It is commonly installed in equipment frames, motor mounts, compressor assemblies, and pump housings where controlled torque and alloy-grade fastener strength are specified.

Key Features

• 1/2-20 UNF thread for high tensile load capacity and vibration resistance
• 2.75 inches length under head with partial threading for precise engagement depth
• 3/8 inch hex socket drive for use with standard hex keys and socket drivers
• Alloy steel construction meets ASTM A574 high-strength fastener requirements
• Black oxide coating provides corrosion inhibition and reduces light reflectance
• Conforms to ASME B18.3 dimensional standards for consistent fitment

Compatibility

Designed as a standard ASME B18.3 hex socket cap screw suitable for use in any application specifying a 1/2-20 UNF partially threaded alloy steel socket head cap screw with a 3/8 inch drive.

Installation Notes

Installation should be performed by a qualified mechanic or maintenance technician using a calibrated torque wrench and a properly sized 3/8 inch hex key or socket driver bit. De-energize and lock out all equipment before replacing or installing fasteners in live assemblies. Do not exceed the torque rating specified by the equipment manufacturer for 1/2-20 UNF alloy steel fasteners. Inspect threads and seating surfaces for damage before installation to ensure full load-bearing engagement.