Product Name rolling door shutter door steel strips C67 material CK67/CK75/C67S/C75S/C67/C75 Color blue polished,polished=bright,white,blue,yellow.etc Techinique cold rolled,annealed,heat treatment with hardened and tempered Hardness 44-48hrc Edge Rounded,Slitted Application band spring,rolling door spring,rolling shutter spring,rolling shuter accessories package each bundle with light oil and plastic film then wrapped in anti-rust paper with metallic pallet
