... 45aaQ345Baa16Mnaa42CrMo, 40CrNiMo 2)O.D:2000mm Thicknes 60mm Length 800mm forged steel ringQuality GB 45,Q345B,16Mn,42CrMo, 40CrNiMo, 20CrNiMo EN C45 ... , 16MnCr5, 42CrMo4, 39NiCrMo3, 18NiCrMo5, 55NiCrMoV7 ASTM 1018, 1045, A105, 4140, 4340, 8620, H13 Size O.D. up toφ2000mm Wall thickness ... as per your request Other qualities could also be supplied forged steel ring