本SAE标准规定了窄环宽R、B和M矩形活塞环类型的基本尺寸特征。尺寸表8和9允许使用铸铁（表8）或钢（表9）。由于钢环的弹性模量高于铸铁环，如果将自由间隙设置为力的基准，则表面压力的波动将更大。因此，使用表面压力作为参考来设置力，以最小化波动的影响。本文件的要求适用于往复式内燃机的矩形环，铸铁环直径不超过90 mm，钢环直径不超过100 mm。它们也可用于在类似条件下工作的压缩机活塞环。

This SAE Standard specifies the essential dimensional features of R, B, and M rectangular piston ring types with narrow ring width.Dimensional tables 8 and 9 allow for the use of cast iron (table 8) or steel (table 9). Since the modulus of elasticity of steel rings is higher than that of cast iron rings, the fluctuation in the surface pressure will become greater if the free gap is set as the reference for force. Therefore, forces are set using the surface pressure as the reference, in order to minimize the effect of the fluctuation.The requirements of this document apply to rectangular rings for reciprocating internal combustion engines up to and including 90 mm diameter for cast iron rings and up to and including 100 mm diameter for steel. They may also be used for piston rings of compressors working under similar conditions.