The ESAB 84Z31 is a specialized replacement component designed for the HW-90 series of TIG welding torches. This item serves as the rear retention mechanism for the torch's electrode assembly. By threading into the back of the torch head, the cap exerts axial pressure on the collet, which in turn compresses against the collet body to firmly grip the tungsten electrode. The 84Z31 is designated as a "short" back cap, often referred to in the industry as a "button" cap, due to its minimal protrusion from the rear of the torch handle.
Constructed from high-grade, heat-resistant phenolic materials, the cap is engineered to withstand the thermal cycling and radiant heat typical of heavy-duty TIG welding applications. It features an integrated O-ring seal which is critical for maintaining the integrity of the shielding gas circuit; a compromised seal at this junction can lead to atmospheric contamination of the weld pool (porosity) and accelerated oxidation of the tungsten electrode. The thread pitch and diameter are machined to precise OEM specifications to ensure smooth engagement with genuine HW-90 torch bodies, preventing cross-threading or gas leaks associated with ill-fitting aftermarket parts.
This product is supplied as a package of two (2) units. The use of a short back cap requires the operator to cut the tungsten electrode to a shorter length to accommodate the reduced internal clearance. This configuration is essential for applications requiring the torch to fit into restricted geometries, such as pipe clusters, internal corners, or complex machinery repairs where the standard long back cap would physically interfere with the workpiece or surrounding structures.
Key Technical Specifications:
| Additional Information |
|---|
| Brand:ESAB |
| Packaging Description:2 PER EA |
| Compatible Torch:HW-90 |
| Component Type:Back Cap |
| Size:Short |
| Material:High-Temperature Phenolic |
