Miller 1/4-20 Black Acorn Lock Nut

Miller 223340 Acorn Nut for Welding Machines

Keep your welding power source secure and professional-looking with the Miller 223340 Acorn Nut. This specialized fastener is a direct replacement for the original hardware found on various Miller welding machines. Often used to secure outer sheet metal panels, covers, or internal assemblies, this nut combines functionality with a clean aesthetic.

Technical Features

The Miller 223340 is precision-engineered with a .250-20 (1/4-20) thread size. It is distinguished by its "Acorn" or cap style, which completely encloses the end of the bolt. This is essential for protecting the bolt threads from weld spatter, dust, and impact. Additionally, the smooth, rounded profile eliminates sharp catch points, enhancing the safety of the equipment's exterior.

Locking Capability

One of the key features of this nut is the "Nylon Interf THDs" (Nylon Interface Threads). This design incorporates a nylon element that deforms elastically over the mating threads. This creates a prevailing torque that locks the nut in position, preventing it from vibrating loose during transport or heavy use. This self-locking feature eliminates the need for separate lock washers, simplifying assembly and maintenance.

Application and Fitment

Finished in black, this nut provides a discreet and corrosion-resistant fastening point. It is commonly used on Miller MIG, TIG, and Stick welders, as well as plasma cutters and fume extractors. If you are missing hardware or have stripped threads on existing nuts, replacing them with the correct OEM part ensures that your machine's enclosure remains properly grounded and secure. Always verify fitment with your machine's parts manual, but generally, this 1/4-20 nut is a staple in the Miller hardware ecosystem.