This document specifies the characteristics of inch based spherical plain bearing, metal to metal, in corrosion resisting steel, narrow series. They are intended for use in fixed or moving parts of the aircraft structure and their control mechanisms. They are used in the temperature range as determined by the grease capability as below: — code A: greased as per MIL-PRF-23827 Type I, operating temperature range −73 °C to 121 °C; — code B: greased as per MIL-PRF-81322, operating temperature range −54 °C to 177 °C. The range of application for bearings lubricated with grease per code A is limited to 121 °C. In both cases the spherical surface of the outer or inner ring are provided with a dry-film lubricant as per MIL-PRF-46010 or equivalent (anti-seizing protection).