217283 - Miller 1/4-20 x 3/4 Grade 5 Carriage Bolt (Pack of 10)

Genuine Miller OEM Hardware for Industrial Maintenance

The Miller 217283 is a package of ten (10) high-quality carriage bolts designed to meet the rigorous specifications of Miller Electric welding equipment. In the realm of industrial maintenance and repair operations (MRO), the integrity of every component matters, down to the smallest fastener. These bolts are manufactured from Grade 5 steel, a medium carbon steel that has been quenched and tempered to provide significant strength advantages over standard Grade 2 hardware. With a proof load of 85,000 psi and a minimum yield strength of 92,000 psi, Grade 5 bolts are essential for structural applications where shear and tensile loads are a concern.

This specific fastener features a 1/4-20 UNC thread pitch and a length of 0.750 inches (3/4 inch). The carriage bolt design is characterized by its smooth, domed head and a square section immediately beneath the head. This square neck is designed to seat into a corresponding square hole in the metalwork, locking the bolt in place and preventing it from rotating when a nut is tightened from the opposite side. This self-locking feature is particularly valuable in the assembly of welding machine chassis, panels, and internal brackets where access to the bolt head may be limited or where a smooth external finish is required to prevent snagging on cables and clothing.

Corrosion resistance is a critical factor for welding equipment that often operates in harsh shop environments or outdoor sites. The Miller 217283 bolts feature a protective plating, likely zinc, which acts as a sacrificial anode to prevent oxidation of the underlying steel. Using genuine OEM hardware ensures that the dimensional tolerances and material properties align perfectly with the original engineering design of your Miller machine. Substituting with generic hardware of unknown grade or finish can lead to premature failure, rust streaks, or fitment issues. This 10-pack quantity allows maintenance teams to stock essential spares, ensuring that minor hardware losses during repair or maintenance do not result in equipment downtime.