This standard specifies the characteristics of rigid single row ball bearings in corrosion resisting steel with a solid or lightweight flanged alignment bush, designed to withstand only slow rotations and slight oscillations under load. They are intended for use in the hubs of torsion lever and in separated supports. The airframe rolling bearings defined in this standard may be used in the temperature range from -54 °C to 150 °C. However, being lubricated with the following greases (see EN 3727): ester type very high pressure grease (code letter A), operating range from -73 °C to 121 °C or, synthetic hydrocarbons type very high pressure grease general purpose (code letter B) operating range from -54 °C to 177 °C. Their field of application when lubricated with code letter A grease is limited to 121 °C.