Value Collection -40879-1 Button Socket Cap Screw 5/16-18

Product Description

The VALUE COLLECTION -40879-1 is a 5/16-18 button socket cap screw designed for secure, low-profile fastening in demanding mechanical and structural applications. Manufactured from alloy steel with a black oxide finish, this fastener delivers corrosion resistance and a clean appearance. The hex socket drive accepts a 3/16-inch hex key for installation in confined spaces where a standard wrench cannot be used. At 5/8 inches in length under the head and fully threaded, it provides consistent thread engagement across the entire shank. Hardness is rated at 36-43 HRC, meeting ANSI/ASME B18.3 and ASTM F835 standards.

This fastener is suited for general mechanical assembly, machine maintenance, and fabrication work across industrial, commercial, and light manufacturing settings. The button head profile reduces snag points on moving assemblies and is commonly used in equipment panels, brackets, guards, and enclosures. The UNC thread standard and 3A thread fit class make it compatible with standard tapped holes in steel, aluminum, and other common base materials. Installers will find this screw appropriate wherever a low-profile cap screw is required and torque access is limited.

Key Features

• Button head profile for low-profile, snag-resistant fastening
• 3/16-inch hex socket drive for use in tight or recessed installation areas
• Alloy steel construction rated 36-43 HRC for high-strength applications
• Black oxide finish provides mild corrosion resistance and reduces glare
• Fully threaded shank with UNC thread standard and 3A fit class
• Meets ANSI/ASME B18.3 and ASTM F835 fastener standards

Compatibility

Designed as a standard UNC 5/16-18 button socket cap screw for use in any application requiring ANSI/ASME B18.3 compliant fasteners with a 3A thread fit class.

Installation Notes

Installation requires a 3/16-inch hex key or Allen driver. Ensure the mating tapped hole is clean, properly sized for a 5/16-18 UNC thread, and free of debris before fastening. Do not exceed the rated hardness limits by applying impact tooling that is not rated for hardened fasteners. Follow applicable mechanical codes and equipment manufacturer torque guidelines for the specific assembly.