Holo-krome 60074 Flat Socket Cap Screw 5/16-18 X 1/2 in

Product Description

The HOLO-KROME 60074 is a flat socket cap screw designed for flush or countersunk fastening applications in metal assemblies. It features an 82-degree flat head profile with a 3/16-inch hex socket drive, allowing installation with a standard hex key. Manufactured from alloy steel with a black oxide finish, the fastener carries a hardness rating of 39-44 HRC, making it suitable for high-stress mechanical connections. The thread is 5/16-18 UNC and fully threaded along its 1/2-inch overall length. Thread fit class is 3A, conforming to ASME B18.3 and ASTM F835 standards. Machinists, maintenance technicians, and OEM assembly personnel are the primary installers.

This screw is used wherever a low-profile, countersunk fastener is required in ferrous or non-ferrous metal components. Common applications include machine tool fixtures, jigs, equipment enclosures, and structural mechanical assemblies requiring a flush surface finish. The black oxide coating provides mild corrosion resistance and reduces light reflection in precision and optical tooling environments. The fully threaded 5/16-18 UNC configuration suits tapped holes in medium-thickness stock where full thread engagement across the entire length is required.

Key Features

• 82-degree flat head seats flush in standard countersunk holes
• 3/16-inch hex socket drive for precise torque application with a hex key
• Alloy steel construction with 39-44 HRC hardness for high-strength fastening
• Black oxide finish for mild corrosion resistance and reduced reflectivity
• Fully threaded 5/16-18 UNC, Thread Fit Class 3A for consistent engagement
• Conforms to ASME B18.3 and ASTM F835 fastener standards

Compatibility

Designed as an OEM-style replacement or standard-service flat socket cap screw for tapped 5/16-18 UNC holes requiring an 82-degree countersink and a flush head profile in mechanical assemblies.

Installation Notes

Installation is performed by machinists or mechanical technicians using a 3/16-inch hex key or hex bit driver. Ensure the mating hole is tapped to 5/16-18 UNC and countersunk to 82 degrees before installation. Degrease mating surfaces and inspect thread condition prior to assembly. Do not exceed the rated hardness class by substituting this fastener in applications specifying a different material grade or thread standard.