1.blue steel strips for rolling shutter part Springs for doors 2.CK67/CS70/SAE1065 3.professional cutting, ... Heat treatment is carried out mainly for reducing sheet thickness, improving surface finishing, preparing the surface for coating and providing a range of ... , blue, polish blueEdge: Mill, Slit, RoundTempers: Full hard, Soft for cold forming. Hardness as per client’s requestForms: Coils, Sheets ...