Why are stainless elements so often affected by rust? One reason: screwdriving jobs are often carried out with a tool made of conventional steel which can result in extraneous rust forming. This is annoying. We were confident that this could be prevented by using tools likewise out of stainless steel and meeting the required standard of industrial hardness. A tool series out of stainless steel. The forming of extraneous rust is prevented and a special vacuum ice-hardening process ensures the required degree of hardness.