172555 - Miller M10-1.5 x 50mm Hex Head Screw, Grade 8.8 Plated

Technical Overview of the Miller 172555 M10-1.5 x 50mm Screw

The Miller 172555 is a specific metric fastener designed for use within Miller Electric welding power sources and industrial equipment. This component is a hex head cap screw featuring an M10 diameter with a standard coarse thread pitch of 1.5mm. The total length of the screw is 50mm, measured from under the head to the end of the threads. It is manufactured to Class 8.8 specifications, which indicates a medium carbon steel construction that has been quenched and tempered. This grade offers a tensile strength of approximately 800 MPa and a yield strength of 640 MPa, making it suitable for structural applications within the machine chassis where significant clamping force is required.

The fastener features a plated finish (denoted by 'PLD' in the specification), typically zinc, which provides a sacrificial anode layer to protect the underlying steel from oxidation and corrosion. This is particularly important in welding environments where humidity and atmospheric contaminants can accelerate rust. The hex head design allows for the application of high torque values using standard metric sockets or wrenches, ensuring a secure assembly that resists loosening due to the high-frequency vibrations often generated by transformer-based or inverter welding power sources.

Using genuine OEM fasteners like the Miller 172555 is critical for maintaining the mechanical integrity of the equipment. Generic fasteners may not meet the specific dimensional tolerances or material grade requirements specified by Miller engineering. Mismatched thread pitches or lower-grade bolts (such as Class 4.6) can lead to stripped threads in the mating component or bolt failure under load. This screw is supplied as a single unit and is a direct replacement for the original part installed at the factory.

Technicians replacing this part should verify the mating thread condition before installation. It is recommended to adhere to standard torque specifications for M10 Grade 8.8 fasteners unless a specific torque value is provided in the machine's service manual. Proper installation ensures the structural rigidity of the welder's frame or the secure mounting of internal heavy components like transformers and inductors.