mattress and spring Grade:55CrSi,60Si2Mn,65Mn Dia:6.0~16.0mm Standards: ASTM, BS, DIN, GB, JIS mattress and springGrade:55CrSi,60Si2Mn,65Mn ... of spring5. Applicable Industriesl: Widely used in automobile, elevator, motorcycle, electric switches, high-speed rail, machinery. Meanwhile, we also can according ... >6.50~7.001430~15801400~15501500~16501630~17801740~18903540 mattress and spring