This Standard specifies methods of calculating the basic dynamic load rating and rating life of rolling bearings designed in accordance with bearings-related standards specified in JIS B 1511, and manufactured by quenching the steel material specified in JIS G 4805 or alloy steel equivalent thereto in quality to an appropriate hardness.
In addition to the methods of calculating the basic rating life, which is the life associated with 90 % reliability with conventional operating conditions, this Standard also specifies methods of calculating the modified rating life, in which various reliabilities, lubrication condition, contaminated lubricant and fatigue load of the bearing are taken into account.
The following should be noted in using this Standard.
— This Standard does not cover the influence of wear, corrosion and electrical erosion on bearing life.
— This Standard is not applicable to designs where the rolling elements operate directly on a shaft or housing surface, unless that surface is equivalent in all respects to the bearing ring (or washer) raceway it replaces.
— Double-row radial bearings and double-direction thrust bearings are, when referred to in this Standard, presumed to be symmetrical.
NOTE: The International Standard corresponding to this Standard and the symbol of degree of correspondence are as follows. ISO 281: 2007 Rolling bearings-Dynamic load ratings and rating life (MOD)
The 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/lEC Guide 21-1.