Holo-krome 640000030 Button Socket Cap Screw 4-40

Product Description

The HOLO-KROME 640000030 is a 4-40 button socket cap screw designed for secure fastening in applications where a low-profile head and high clamping strength are required. The button head design reduces protrusion above the mating surface, making it well-suited for installations with limited clearance. Driven by a 1/16-inch hex socket, this fastener is fully threaded along its 5/16-inch length under head. Constructed from alloy steel with a black oxide finish, it meets ANSI/ASME B18.3 and ASTM F835 standards and carries a 3A thread fit class for precise engagement.

This screw is used in light mechanical assemblies, electronics enclosures, fixtures, and precision equipment where a compact fastener with reliable thread engagement is needed. The 4-40 UNC thread pattern is a common size in both commercial and industrial applications. Installation is typically performed by machinists, maintenance technicians, or assembly personnel. The right-hand thread direction and 3A class fit make it compatible with standard 4-40 tapped holes.

Key Features

• Button head profile for low-clearance installations
• 1/16-inch hex socket drive for precise torque application
• Fully threaded 5/16-inch length under head
• Alloy steel construction with black oxide finish for corrosion resistance
• Meets ANSI/ASME B18.3 and ASTM F835 fastener standards
• 3A thread fit class for consistent and accurate thread engagement

Compatibility

Designed as a standard 4-40 UNC button socket cap screw suitable for use in any application requiring a 4-40 tapped hole and a low-profile fastening solution.

Installation Notes

Install using a 1/16-inch hex key or socket driver. Ensure the mating threaded hole is clean and free of debris before installation. Do not exceed the rated hardness limits of the mating material to avoid thread stripping. This fastener is sold in multiples of 100 units minimum.