... .Characteristics of torsion spring:1)Including Single Torsion Spring,Dual Torsion Spring 2)The Torsion Spring used in car ... low3)Go thorugh TS16949,ISO14001,OHSAS18001XIAMEN HONGSHENG - HARDWARE SPRING CO.,LTD. has been manufacturing Technical Springs since ... technology in the manufacture of the products. XIAMEN HONGSHENG - HARDWARE SPRING CO.,LTD. manufactures high precision springs laying ...