The surface SPIN Ferrit is not a stainless product. SPIN Ferrit is a hot-rolled steel material which is colored partly cobalt blue during the cooling process. In the predominant areas the ferrite steel got grey nuances and also rolled-in slag is characteristic for its natural surface. Some slight rust approach are sometimes visible also. The only surface protection is a wax layer which is coated during the production already and which will be renewed over a addition to the cleaning water during the regular maintenance.