Boosting Performance in Hydraulic Systems with Alternative Coatings

In 2017, the REACH (Registration, Evaluation, Authorization, and Restriction of CHemicals) directive placed restrictions on the use of any coating or plating using hexavalent chromium (CR6) to protect humans and the environment from potentially harmful chemicals. As a result, alternative coatings are becoming more common for coating piston rods in hydraulic systems; however, most surface-finish guidance from seal suppliers is still based on 2D finish characteristics for use with chromium layers. This can significantly affect performance and system life in hydraulic systems because the lubrication within these systems is fundamentally affected by the surface finish of the mating surfaces.