scope:

This Standard specifies the bearing and subunit dimension series and boundary dimensions for complete single-row, double-row and matched pair of tapered roller bearings (hereafter referred to as bearings). It also specifies the flange dimensions of flanged outer rings for a selection of these bearings.

NOTE 1 Boundary dimensions of tapered roller bearings are also covered by JIS B 1534 ^[2]. While this Standard specifies dimension series and boundary dimensions, JIS B 1534 ^[2] provides a selection of generally used bearing boundary dimensions derived from this Standard and the corresponding designations.

NOTE 2 The International Standard corresponding to this Standard and the symbol of degree of correspondence are as follows.

ISO 355 : 2019 Rolling bearings - Tapered roller bearings - Boundary dimensions and series designations (MOD)

In addition, symbols which denote the degree of correspondence in the contents between the relevant International Standard and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO/IEC Guide 21-1.