The ESAB 28Z85 is a specialized compression spring designed specifically for the tensioning mechanisms within ESAB wire feed assemblies. In the context of Gas Metal Arc Welding (GMAW) and Flux Cored Arc Welding (FCAW), the consistency of wire delivery is paramount to arc stability. The drive roll system relies on a precise normal force applied to the welding wire to generate sufficient friction for feeding without deforming the wire itself. This normal force is generated by the pressure spring, which acts upon the pressure arm or idle roll assembly.
Over time, springs utilized in industrial environments are subject to fatigue and thermal cycling, which can alter their spring constant (k). A degraded spring may no longer provide the linear force required to maintain the optimal grip on the wire, leading to micro-slippages that manifest as erratic arc characteristics or burn-back. The 28Z85 is engineered to OEM specifications to ensure it delivers the exact force curve required by ESAB drive systems. Its dimensions—approximately 1.5 inches in length and 0.72 inches in diameter—are calibrated to fit the housing tolerances perfectly, preventing buckling or misalignment during operation.
This component is manufactured from high-grade spring steel, treated to resist relaxation under load. It is an essential maintenance item for technicians troubleshooting feed issues. When replacing drive rolls or performing preventative maintenance on the feeder, inspecting the pressure spring for length reduction or permanent set is a critical step. Installing a genuine ESAB 28Z85 ensures that the mechanical subsystem of your welder operates within its design parameters, preserving the longevity of the motor and gearbox by preventing over-tightening (a common compensation for weak springs).
Key Technical Specifications:
| Additional Information |
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| Packaging Description:pack of 1 |
| Product Type:Pressure Spring |
| Material:Spring Steel |
| Application:Wire Drive Tensioning |
