Value Collection -40878-2 Button Socket Cap Screw 50 Pack

Product Description

The VALUE COLLECTION -40878-2 is a button socket cap screw designed for applications requiring a low-profile fastening solution with high strength and corrosion resistance. Manufactured from alloy steel with a black oxide coating, this screw features a 5/16-18 UNC thread and measures 1/2 inch in length under the head. The button head profile reduces surface protrusion, making it suitable for assemblies where clearance is limited. Hardness is rated at 36-43 HRC, meeting the mechanical requirements of ANSI/ASME B18.3 and ASTM F835. This package contains 50 pieces. Installed by millwrights, maintenance technicians, and assembly professionals across industrial and commercial applications.

This screw is suited for use in general mechanical assemblies, machinery guards, enclosures, brackets, and fabricated steel components where a flush or near-flush fastener profile is required. The black oxide finish provides mild corrosion resistance and reduces light reflection, making it a common choice in both industrial maintenance and precision fabrication settings. The 3/16-inch hex socket drive accommodates standard hex keys and socket drivers.

Key Features

• Button head profile keeps fastener low-profile for clearance-sensitive assemblies
• Alloy steel construction with 36-43 HRC hardness rating per ASTM F835
• Black oxide coating for mild corrosion resistance and reduced reflectivity
• 3/16-inch hex socket drive for use with standard hex keys or socket tools
• 5/16-18 UNC fully threaded, Class 3A thread fit for precise engagement
• Meets ANSI/ASME B18.3 and ASTM F835 fastener standards
• Sold in a 50-piece package with a minimum order quantity of 1

Compatibility

Designed as an OEM-style replacement or stock fastener for general industrial and mechanical assemblies requiring a 5/16-18 UNC button socket cap screw in alloy steel with black oxide finish.

Installation Notes

Installation is performed using a 3/16-inch hex key or socket driver. De-energize or lock out any equipment before accessing fastener locations in live machinery per applicable OSHA lockout/tagout procedures. Do not exceed the rated torque specifications published in ANSI/ASME B18.3 guidelines for this thread size and material class. Inspect threads for damage before installation to ensure proper Class 3A engagement.