... 1.Type:sprial 2.Bearing way:Torsion 3.Material:carbon steel SUS301 4.Occation:safety belt Enterprise introduction As specilized precise ... :coin,spiral,cylinder2.Bearing way:Torsion,compression,extension3.Material:stainless steel ,carbon steel(Japan SUS301)4.Size:depend on you5.Use occasion ... mbile,auto car,furniture,industrial,motorcycle and so on. Carbon steel spring for retractable stachion post