57Y04 - Short Back Cap for 17/18/26 Series TIG Torches (2-Pack)

Technical Overview of the ESAB 57Y04 Short Back Cap

The ESAB 57Y04 Short Back Cap is a specialized consumable designed for Gas Tungsten Arc Welding (GTAW) applications requiring a compact torch profile. Engineered to fit standard 17, 18, and 26 series TIG torch bodies (including WP-17, WP-18, WP-26, and their equivalents from major manufacturers like Weldcraft and Miller), this component is essential for maintaining the functional integrity of the torch assembly. The back cap serves two primary technical functions: it applies axial force to the collet, compressing it against the collet body to securely grip the tungsten electrode, and it creates a gas-tight seal at the rear of the torch head to prevent atmospheric contamination of the shielding gas stream.

Constructed from high-durability phenolic compounds and reinforced with brass threading, the 57Y04 is built to withstand the high thermal cycles and radiant heat typical of TIG welding environments. The inclusion of a fitted O-ring ensures a positive seal, maintaining consistent gas flow and pressure. Unlike standard long back caps which accommodate full-length tungsten electrodes, this short variant requires the use of shorter tungsten segments (stubby tungsten), thereby reducing the overall length of the torch assembly. This modification is critical for industrial MRO and fabrication tasks where clearance is limited, such as pipe welding in racks or repair work inside machinery housings.

This product is supplied as a package of two, ensuring that operators have a replacement unit readily available. The universal 57Y04 form factor ensures cross-compatibility with a wide range of air-cooled and water-cooled torches, making it a versatile inventory item for welding shops. Proper installation requires hand-tightening to avoid thread damage while ensuring sufficient compression on the collet for electrical conductivity and electrode stability.