For harsh environments and rough handling conditions, the nsd tupH sealed surface conversion system provides corrosion protection that penetrates deep below the drive surface. The treatment is available for worm, helical inline and helical bevel gearboxes; smooth-surface motors; distributed frequency inverters; and motor starters with an aluminum casing. Die-cast aluminum casings feature good thermal performance and a lower weight than cast-iron or stainless steel versions. The drives can be cleaned with high-pressure steam jets. The drive surface is hardened to become impact-resistant. No coating is applied, so the corrosion protection cannot be impaired by scratches or chipping.