... coil(t)12-45mm60-245mm205-423mm4-823-121.Elements: internal spring and external spring2.Materials: 60Si2Mn, 60Si2MnA, 60Si2CrVA, 60Si2CrVAT,50 CrV4 ... , Pakistan, Namibia, Venezuela, Burma, Thailand, Angola,Sudan, Australia, etc5.Besides, springs can be manufactured according to customer's requirement.6.Package ...