auto springs: 1.Wire Diameter:d=1.50mm to 5.15mm; 2.The Outer Diameter of the Spring:d=13 mm to 35 mm. 3.ISO9001&TS16949 We offer some kinds of auto springs for plunger ,valve, control valve ,rubber valve and so on . They were used in Santana,Hongqi,Jetta and some kinds of motorcycles.Our company can produce the best priducts with the cheaper price .1. Applications: piston back position, valves, ...