In the field, excavator cylinders face extreme pressure spikes and high-frequency vibrations. Unlike standard polyurethane seals that can suffer from frictional heat buildup, our Bronze-filled PTFE compound offers a significantly higher melting point and superior thermal conductivity. This material prevents “stick-slip” (shuddering) and ensures the seal maintains its structural integrity at temperatures ranging from -30°C to +110°C. The bronze reinforcement provides the necessary hardness to resist “cold flow” and extrusion into the clearance gap under loads up to 400 Bar.

For service technicians, the 38*48.7*4.2 Step Seal is designed for reliable field installation. Its 4.2mm cross-section allows for a compact piston design, but precision is required during assembly. We recommend using a mounting sleeve to prevent the PTFE lip from being nicked by sharp cylinder threads. Because this is a single-acting seal, it is typically installed in back-to-back pairs for double-acting pistons. This configuration provides the ultimate “dry” seal performance, extending the service life of the cylinder and reducing the frequency of hydraulic fluid top-offs.