Holo-krome 720000270 Hex Socket Cap Screw 4-40 Unc

Product Description

The HOLO-KROME 720000270 is a hex socket cap screw designed for precision fastening in demanding mechanical assemblies. Threaded to the 4-40 UNC standard, this fastener features a 3/32-inch hex drive socket and a 1-1/4-inch length under head with partial threading. Constructed from alloy steel and finished with a black oxide coating, it delivers solid corrosion resistance and maintains dimensional accuracy under torque load. This screw conforms to ASME B18.3 and ASTM A574 standards, making it suitable for applications where mechanical strength and consistent fitment are required. It is commonly installed by mechanical technicians, maintenance professionals, and precision assembly tradespeople.

This fastener is well suited for light-gauge metal assemblies, precision instruments, HVAC control panels, electrical enclosures, and other applications that require a compact, high-strength socket cap screw in the 4-40 UNC thread size. The black oxide finish makes it appropriate for indoor and semi-protected environments where appearance and moderate corrosion resistance are both considerations. Partial threading ensures proper clamping force in standard through-hole and tapped-hole configurations.

Key Features

• 4-40 UNC thread size for compatibility with fine-thread tapped holes in thin materials
• 3/32-inch hex socket drive for use with standard hex keys and Allen wrenches
• 1-1/4-inch length under head with partial threading for proper clamp load
• Alloy steel construction meets ASTM A574 mechanical strength requirements
• Black oxide finish provides corrosion inhibition and reduced light reflection
• Conforms to ASME B18.3 dimensional standard for socket cap screws

Compatibility

Designed as an OEM-style replacement or standard-service fastener for any application requiring a 4-40 UNC partially threaded hex socket cap screw conforming to ASME B18.3 and ASTM A574.

Installation Notes

Installation should be performed by a qualified mechanical technician using a calibrated 3/32-inch hex key or Allen driver. Ensure the receiving tapped hole is clean and free of debris before threading. Do not exceed the rated drive engagement depth, and avoid over-torquing, which can strip threads in fine-pitch 4-40 tapped holes. Consult applicable mechanical or equipment standards for torque guidelines specific to the assembly.