Holo-krome 72142 Socket Head Cap Screw 5/16-18 X 2-3/4 in

Product Description

The HOLO-KROME 72142 is a partially threaded socket head cap screw designed for high-strength fastening applications in mechanical assemblies, tooling, fixtures, and industrial equipment. Built from alloy steel with a black oxide finish, this screw meets ASTM A574 and ASME B18.3 standards, making it a reliable choice for precision fastening where consistent clamping force and dimensional accuracy are required. The 5/16-18 thread size and 2-3/4 inch length under head make it suitable for moderate-depth through-hole and tapped-hole applications. A 1/4 inch hex drive allows installation with standard socket head drivers. Partial threading provides a smooth shank section for shear-load applications and precision location.

This screw is used across a wide range of commercial and industrial settings including machine shops, maintenance operations, OEM assembly lines, and field service work. The black oxide finish provides mild corrosion resistance and reduces light reflection in precision instrument and tooling environments. Electricians, millwrights, pipefitters, and general maintenance mechanics routinely install this type of fastener in panel mounting, bracket fabrication, and structural assembly tasks where a recessed hex drive is needed for torque control in confined spaces.

Key Features

• Alloy steel construction meets ASTM A574 high-strength fastener standard
• Conforms to ASME B18.3 dimensional standard for socket head cap screws
• Partially threaded shank supports shear loading and precise part location
• Black oxide finish provides mild corrosion resistance and low-reflectance surface
• 1/4 inch internal hex drive for use with standard Allen or hex key drivers
• 5/16-18 UNC thread form for broad compatibility with standard tapped holes

Compatibility

Designed as a standard-dimension socket head cap screw per ASME B18.3, compatible with any 5/16-18 UNC tapped hole requiring a partially threaded fastener at 2-3/4 inch length under head.

Installation Notes

Installation is typically performed by millwrights, maintenance mechanics, or assemblers using a 1/4 inch hex key or hex-bit driver. Always ensure the mating tapped hole is clean, free of debris, and of sufficient thread depth before driving. Apply appropriate thread lubricant or thread-locking compound per the assembly specification. Power down and de-energize any equipment before accessing fastened assemblies on live machinery.