SUS Metric heavy-duty extension springs 1,Products DetailesMaterial1.Stainless Steel: SS201, SS303, SS304, SS316, SS410, SS4202,Steel:C45(K1045), C46(K1046),C203.Brass ... after sales. 2,Factory overview 3, Warehouse and Workshop show 4,Manufacture Process 5,Quality Control 6, Strong Package 7,Customer ...