690516 - ESAB ST-21 Replacement Inlet Guide

Precision Wire Guidance for ST-21 Systems

The ESAB ST-21 Inlet Guide (Part Number 690516) is a critical replacement component designed to maintain the operational integrity of ESAB ST-21 MIG welding guns. In high-performance industrial welding environments, the consistency of wire delivery is paramount to achieving sound welds and maintaining productivity. The inlet guide serves as the primary interface between the wire feeder drive rolls and the torch liner, a junction where misalignment can lead to significant operational issues.

Manufactured to ESAB's exacting OEM specifications, this inlet guide features a precision-machined bore that ensures the welding wire is directed concentrically into the liner. This precise alignment minimizes friction and drag, which are common culprits in voltage fluctuations and irregular arc characteristics. By using genuine ESAB parts, operators ensure that the tolerances match perfectly with the ST-21 rear connector assembly, preventing the gaps or offsets that often occur with aftermarket generic replacements.

Over time, the abrasive nature of welding wire—particularly flux-cored or hard wires—can groove or wear down the internal surface of an inlet guide. This wear can create sharp edges that shave the wire, leading to the accumulation of debris within the liner and eventual clogging. Replacing the inlet guide with the 690516 model restores the smooth, low-friction path required for optimal wire feed speed and arc stability. It is an essential spare part for maintenance teams managing fleets of ST-21 equipment.

Key Technical Benefits:

• OEM Compatibility: Guaranteed fit for ST-21 series torches, eliminating installation guesswork.


• Wear Resistance: Constructed from durable materials designed to withstand the constant friction of moving wire.


• Feed Optimization: Reduces drag at the feeder-to-torch transition, lowering the load on the drive motor.