Holo-krome 86172 Hex Socket Cap Screw 4-40 Unc 7/8 in

Product Description

The HOLO-KROME 86172 is a hex socket cap screw engineered for precision fastening in mechanical assemblies, fixtures, and equipment. It features a 4-40 UNC thread size with a 7/8-inch length under head and is fully threaded along its entire shank. The drive is a 3/32-inch internal hex socket, designed for use with a standard Allen key or hex bit driver. Constructed from alloy steel with a black oxide finish, this screw delivers solid tensile strength and moderate corrosion resistance in controlled environments. It meets ASME B18.3 and ASTM A574 standards, making it a reliable choice for applications where dimensional and mechanical consistency matter.

This screw is well suited for light mechanical assemblies, instrument panels, jigs, fixtures, and machine components where a low-profile socket head and full thread engagement are required. The 4-40 UNC thread is a fine-pitch unified coarse thread commonly used in small-diameter fastening applications across industrial, electronic, and mechanical equipment. Technicians and machinists working on precision assemblies will find the hex socket drive useful in confined spaces where a standard screwdriver cannot reach. This item is sold individually but requires a minimum order of 100 units.

Key Features

• 4-40 UNC thread size with 7/8-inch length under head for consistent engagement depth
• Fully threaded shank provides maximum thread contact throughout the fastened joint
• 3/32-inch hex socket drive allows torque application in tight clearance areas
• Alloy steel construction meets ASTM A574 mechanical property requirements
• Black oxide finish provides moderate corrosion resistance and reduces light reflection
• Conforms to ASME B18.3 dimensional standards for hex socket cap screws

Compatibility

Designed as a standard ASME B18.3 hex socket cap screw suitable for threaded holes or nuts with 4-40 UNC internal threads in mechanical assemblies, fixtures, and precision equipment.

Installation Notes

Installation is performed by machinists, maintenance technicians, or assemblers using a 3/32-inch hex key or hex bit driver. Ensure the mating threaded hole or nut is clean and free of debris before driving the screw. Do not over-torque small-diameter screws, as alloy steel cap screws at this size are susceptible to thread stripping if torque is applied beyond manufacturer specifications. Follow applicable equipment assembly procedures and relevant standards for fastener installation in the application.