Door extension/tension spring 1.ISO90001&ISO14001quality control 2.wire dia.: 0.08mm -- 10.0mm 3.Free Sample is available Door ... style are made by drawings.OEM & ODM accepted2.Material:Spring steel,stainless steel,zinc plating steel,etc. 3.Surface ... all kinds of springs,like brake spring,waved spring,tension spring,wire formed spring,compression spring,torsion spring ect.We also good provide hardware ...