279718 - Miller 1/2-20 x 0.87 Hex Head Screw Grade 5

Genuine Miller 279718 Replacement Hardware

The Miller 279718 Screw is a specialized fastening component designed specifically for Miller Electric welding power sources and industrial equipment. Engineered to meet Grade 5 specifications, this hardware offers a significant upgrade in tensile strength compared to standard Grade 2 fasteners often found in general hardware stores. The screw features a .500-20 (1/2-20) UNF fine thread pitch. Fine threads are particularly advantageous in high-vibration environments—such as inside a running welding generator or industrial power source—because they have a larger minor diameter and a smaller helix angle, providing better resistance to loosening over time and higher tensile strength.

Measuring 0.87 inches in length, this hex head screw is plated with a clear finish (likely zinc chromate) to provide essential corrosion resistance. In industrial environments where humidity, fumes, and temperature fluctuations are common, using unplated or black oxide fasteners can lead to premature rusting, which may seize the bolt or compromise the electrical ground path if the screw is used in a chassis connection. The hex head design ensures that high torque can be applied securely using standard socket or wrench sets, minimizing the risk of cam-out or head stripping during maintenance procedures.

Using genuine OEM parts like the Miller 279718 ensures that the fit, finish, and material properties match the original engineering requirements of your machine. Whether you are replacing a lost fastener during a routine service or rebuilding a unit after a repair, adhering to the manufacturer's bill of materials is critical for safety and longevity. This screw is sold individually, allowing technicians to order the exact quantity required for their specific repair job without accumulating unnecessary surplus.

Technical Specifications:

• Part Number: 279718
• Thread Size: 1/2-20 UNF (Fine Thread)
• Length: 0.87 Inches
• Grade: Grade 5 (Medium Carbon Steel, Quenched and Tempered)
• Head Style: Hexagon
• Finish: Plated Clear