39V99 - ESAB ST-21M MIG Gun Conduit Liner, 6 ft, .035-1/16 in

Technical Overview of the ESAB 39V99 Conduit Assembly

The ESAB 39V99 is a specialized conduit assembly designed for use with the ST-21M series of MIG welding guns. As a critical component in the wire feeding system, this liner ensures the consistent delivery of welding wire from the feeder mechanism to the contact tip. The assembly is manufactured to precise OEM specifications, ensuring seamless compatibility with ESAB and legacy L-Tec ST-21M equipment.

This specific conduit features a length of 6 feet, matching the cable assembly length of compatible torch configurations. It is engineered to handle a broad range of wire diameters, specifically from 0.035 inches (0.9 mm) up to 1/16 inches (1.6 mm). This versatility allows operators to switch between common wire sizes without necessarily changing the liner, provided the wire type remains compatible with the liner material.

Constructed from high-grade coiled steel, the liner provides the necessary rigidity to prevent kinking while maintaining enough flexibility to navigate the torch cable's curvature. Proper maintenance of the conduit is essential for arc stability; a worn or clogged liner can increase friction, leading to erratic wire feed speeds and potential burn-back issues. The 39V99 serves as a direct replacement part, simplifying maintenance and minimizing downtime in industrial welding environments.