Holo-krome 64002 Button Socket Cap Screw 4-40 1/4 in

Product Description

The HOLO-KROME 64002 is a 4-40 button socket cap screw designed for applications requiring a low-profile head with reliable clamping force. It features a hex socket drive sized at 1/16 inch and a fully threaded shank measuring 1/4 inch under the head. Made from alloy steel with a black oxide finish, this fastener meets ANSI/ASME B18.3 and ASTM F835 standards. The 3A thread fit class and right-hand UNC thread form ensure consistent, predictable engagement. With a hardness rating of 38 HRC, it delivers the shear and tensile strength that precision assembly and mechanical sub-assemblies demand.

This screw is suited for machine assembly, fixture building, electronics enclosures, and light structural applications where a flush, rounded head profile is preferred over a standard hex cap. The small 4-40 thread size makes it a common choice in instrumentation, panel fabrication, and tight-clearance assemblies. Licensed machinists, millwrights, and precision assembly technicians are the typical installers. The black oxide finish provides mild corrosion resistance and reduces light reflection in optical or electronic assemblies.

Key Features

• Button head profile reduces snag risk and provides a clean low-profile appearance in finished assemblies
• 1/16 inch hex socket drive for precise torque application in confined spaces
• Alloy steel construction with 38 HRC hardness for high shear and tensile strength
• Black oxide finish offers mild corrosion resistance and a non-reflective surface
• Fully threaded 4-40 UNC shank with 3A thread fit class for consistent engagement
• Meets ANSI/ASME B18.3 and ASTM F835 fastener standards

Compatibility

Designed as an OEM-style replacement or standard-stock button socket cap screw for any 4-40 UNC tapped hole application requiring an ANSI/ASME B18.3 compliant fastener.

Installation Notes

Install using a calibrated 1/16 inch hex key or hex socket bit driver. Ensure the mating tapped hole is clean and free of debris before threading. Do not exceed the torque capacity appropriate for the 4-40 thread size and alloy steel grade. Follow applicable ASME or equipment manufacturer torque guidelines for the assembly.