The housings used in SKF ConCentra roller bearing units are made of grey cast iron.
Paint, corrosion protection
The housings are painted black (RAL 9005) using a water based alkyd/acryl paint. The paint protects the housing in accordance with ISO 12944-2:1998, corrosivity category C2 (i.e. exterior atmospheres with low level of pollution, interior atmospheres where condensation may occur). The paint is not affected by most lubricating or engine oils, cutting fluids or alkalescent washing chemicals. Housings can be repainted with most water or solvent based 1- or 2-component paints.
Unpainted surfaces are protected by a solventless rust inhibitor.