Holo-krome 72390 Hex Socket Cap Screw 1-8 Unc Alloy Steel

Product Description

The HOLO-KROME 72390 is a partially threaded hex socket cap screw engineered for high-strength fastening applications in industrial and mechanical assemblies. It features a 1-8 UNC thread, a 6-inch length under head, and a 3/4-inch hex drive socket for use with standard hex keys or Allen wrenches. The fastener is manufactured from alloy steel and finished with a black oxide coating that provides moderate corrosion resistance and reduces surface glare during installation. It meets ASME B18.3 and ASTM A574 standards, confirming tensile strength and dimensional conformance expected of socket cap fasteners in demanding service environments. Mechanical contractors, millwrights, and maintenance technicians commonly spec this size for structural and equipment mounting work.

This socket cap screw is suited for use in machinery frames, structural fixtures, tooling plates, and heavy equipment assemblies where a recessed-drive fastener is required to clear adjacent components or provide a flush profile. Partial threading allows the unthreaded shank to act as a shoulder section in through-hole or close-tolerance applications, improving shear resistance and alignment in bolted joints. It is appropriate for both original equipment assembly and maintenance replacement in industrial settings.

Key Features

• 1-8 UNC thread form for compatibility with standard coarse-thread tapped holes in that size range
• 6-inch length under head with partial threading, providing an unthreaded shank for shear-load and alignment applications
• 3/4-inch hex socket drive for use with standard hex keys or Allen-type drivers
• Alloy steel construction for high tensile and yield strength per ASTM A574
• Black oxide finish for moderate corrosion resistance and reduced surface reflection
• Conforms to ASME B18.3 dimensional standards for socket head cap screws

Compatibility

Designed as a direct-fit socket head cap screw for tapped assemblies requiring a 1-8 UNC coarse thread and 6-inch grip length. Suitable wherever ASME B18.3 and ASTM A574 socket cap screws are specified.

Installation Notes

Installation should be performed by a qualified mechanic or millwright using a properly sized 3/4-inch hex key or T-handle driver. Ensure the mating tapped hole is clean and free of debris before threading to avoid cross-threading or galling. Apply thread lubricant or anti-seize compound as required by the assembly specification to achieve accurate clamp load. Follow applicable torque specifications from the equipment manufacturer or relevant industry standard for the fastener size and material grade.