Holo-krome 73136 Hex Socket Cap Screw 1/2-20 Unf Alloy Steel

Product Description

The HOLO-KROME 73136 is a hex socket cap screw designed for high-strength fastening applications in mechanical assemblies, industrial equipment, and trade installations. Threaded 1/2-20 UNF and fully threaded along its 1-3/4 inch length under head, this screw is driven with a 3/8 inch hex key. The alloy steel construction with a black oxide finish provides corrosion resistance and maintains surface hardness in demanding environments. It meets ASME B18.3 and ASTM A574 standards, making it suitable for applications where tensile strength and dimensional consistency are required. HVAC, plumbing, and mechanical contractors use socket cap screws like this one in equipment mounting, panel assembly, and structural fastening work.

This screw is suited for use in tight-clearance installations where a standard hex head wrench cannot reach, as the recessed hex drive allows the fastener to sit flush or below the surface. Its fine UNF thread pitch provides stronger thread engagement in thinner materials and offers better resistance to loosening under vibration. Typical applications include equipment frames, motor mounts, valve bodies, and mechanical enclosures in both residential and light commercial service environments.

Key Features

• 1/2-20 UNF thread size for fine-pitch engagement and vibration resistance
• Fully threaded 1-3/4 inch length under head for maximum thread contact
• 3/8 inch hex socket drive for use in confined or recessed locations
• Alloy steel construction meets ASTM A574 high-strength requirements
• Black oxide finish provides mild corrosion resistance and reduces light reflection
• Conforms to ASME B18.3 dimensional standards

Compatibility

Designed as an OEM-style and aftermarket replacement hex socket cap screw for mechanical assemblies requiring a 1/2-20 UNF fully threaded fastener with a 3/8 inch hex drive and ASME B18.3 dimensional compliance.

Installation Notes

Installation is performed by qualified mechanical, HVAC, plumbing, or electrical tradespeople using a calibrated torque wrench and the appropriate 3/8 inch hex key or socket bit. Always de-energize equipment and relieve any system pressure before removing or replacing fasteners in pressurized or energized assemblies. Do not over-torque alloy steel socket cap screws, as stripping the drive socket or exceeding the material yield point can compromise joint integrity. Follow applicable ASME or equipment manufacturer torque guidelines for 1/2-20 UNF alloy steel fasteners.