The boundary dimensions of needle roller bearings of series RNA 48, RNA 49, NA 48 and NA 49 conform to ISO 1206-1982 and those of series NA 69 to ISO 15:1998. The dimensions of the other needle roller bearings listed in the tables are not standardized but have found general acceptance in industry.
NK, NKS, RNA
NKI, NKIS, NA
RNAO
NAO