IR inner rings, finely machined, according to DIN 620. Supplementary marking EGS. Inner rings are made of hardened rolling bearing steel and have finely machined or ground raceways. Inner rings are required for needle sleeves, needle bushes, and needle crowns 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 marking EGS describes a torsion-free ground surface for radial shaft seals according to DIN 3760 and DIN 3761.