... ASTM, BS, DIN, GB, JIS mattress spring wire Grade:55CrSi,60Si2Mn,65Mn Dia:6.0 ... JISAdvantage:1. Marerial: we select good quality spring steel wire rod.2. Surface treatment: advanced technology ... life of spring5. Applicable Industriesl: Widely used in automobile, elevator, motorcycle, electric switches, high- ... strength level for spring steel wire. Mechanical property of steel wire in static level and ...