... steel wire or oil temperd steel wire offer good performance tension spring4mm to 20mm wire diameter rangehigh carbon steel wire or ... exporter in CHina, we manufacture all kinds of spring tines for Tractor, Harrow,Rake,Teeder,Baler,Harvester,Tillage,Cultivator and other ... Parts, mainly produce zig zag springs and bonnell springs, used for sofa, seat, mattress and other furniture.We also make baby ...