R-ring is the equivalent of metal Raschig ring. Since 1914 when F.Raschig invented this type of ring for tower packing, random tower pickings have been developed extensively. The T.C.I R-ring is now used in many applications, but particularly in supporting catalyst beds. Metal T.C.I -R-rings are available in a wide range of carbon and stainless steels.and ceramic, PTFE, PP, etc. Metal Raschig rings’ characteristics Size （mm） Bulk density （kg/m3） Number per m3 Surface area （m2/m3） Free volume 15×15×0.3 379 230000 350 95 25×25×0.4 318 51000 216 96 25×25×0.5 400 51000 220 95 35×35×0.8 430 19000 150 93 50×50×0.5 203 6500 106 97.4 50×50×0.7 285 6500 108 96.4 50×50×0.8 325 7000 109 95 76×76×0.8 212 1830 69 97.3 80×80×1.2 300 1600 65 96 90×90×1.0 236 1160 62 97 All of the given weights refer to the stainless（AISI304）