If stainless steel tanks need to be filled, this requires internally ground stainless steel pipes. The surface quality required to conduct liquids or gases in a hygienic or technically processed manner naturally also places demands on the inner surface of the pipes. The intended use of the media primarily determines the Ra value. During production, whether refining or handling in food production or for medical products, absolutely top-quality surface finishes must be achieved. Even with internally ground hollow steels, these can be as high as Ra values of 0.2µ.