IR inner rings, finely machined, according to DIN 620, with the supplementary designation EGS. Inner rings are made of hardened rolling bearing steel and have finely machined or ground raceways. They are required for needle sleeves, needle bushes, and needle cages when the shaft cannot be used as a raceway. Chamfers on the end faces allow for easy insertion into the bearings and prevent damage to the sealing lips of the bearings. The supplementary designation EGS describes torsion-free ground surfaces for radial shaft sealing rings according to DIN 3760 and DIN 3761.