... We are Manufacturers, Exporters, Designers and OEM Suppliers of all types of Spring. Material55CrSi,60Si2Mn,60Si2MnA,60Si2CrA,60Si2CrVA,etcWire Diameter0. ... 4mm~80mmFree Hight10mm~1188mmHardness42HRC~52HRCDirection of CoilsRight,LeftTotal CoilsAs per Drawing / Data.Load Bearing ... FormedNoteThe materials and specifications can be decided by the customers.