Holo-krome 60138 Flat Socket Cap Screw 1/2-13 X 2-1/2 in

Product Description

The HOLO-KROME 60138 is a flat socket cap screw designed for applications requiring a low-profile, flush-mount fastener with high tensile strength. Manufactured from alloy steel with a black oxide finish, this screw measures 1/2-13 thread size by 2-1/2 inches in overall length and is partially threaded. The 82-degree flat head seats flush into a countersunk hole, reducing protrusion in finished assemblies. Drive engagement is via a 5/16-inch hex socket. With a hardness rating of 39-44 HRC and a Thread Fit Class of 3A, this fastener is built for precision and load-bearing service in mechanical and structural applications.

This flat socket cap screw is suited for use in machine assemblies, fixture building, tooling plates, and structural connections where a flush head profile is required. The UNC thread form and ASME B18.3 and ASTM F835 compliance make it appropriate for demanding industrial and manufacturing environments. It is installed by machinists, millwrights, and maintenance technicians working with ferrous and non-ferrous assemblies. The black oxide finish provides moderate corrosion resistance and reduces light reflection in precision applications.

Key Features

• 82-degree flat head seats flush into countersunk holes for a low-profile installation
• 5/16-inch hex socket drive for standard Allen key or hex bit installation
• Alloy steel construction with 39-44 HRC hardness for high-strength load-bearing use
• Black oxide finish for mild corrosion resistance and reduced surface reflectivity
• Partially threaded shank for improved shear resistance and accurate hole alignment
• Meets ASME B18.3 and ASTM F835 fastener standards

Compatibility

Designed as an OEM-style replacement or direct-use flat socket cap screw conforming to ASME B18.3 and ASTM F835 standards, compatible with standard 1/2-13 UNC tapped holes and countersunk assemblies requiring an 82-degree flat head profile.

Installation Notes

Installation should be performed with a properly sized 5/16-inch hex key or socket bit to avoid rounding the drive recess. Ensure the mating countersink is machined to an 82-degree included angle for full head seating. Follow applicable torque specifications from ASME or fastener manufacturer references for the 1/2-13 thread class. De-energize and lock out any machinery before fastener replacement or adjustment.