本SAE标准规定了窄环宽型HK-和HKB-半梯形环的基本尺寸特征。尺寸和允许使用铸铁（表6）或钢（表7）。由于钢环的弹性模量高于铸铁环，如果将自由间隙作为力的参考，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半梯形环，铸铁环直径不超过70mm，钢环直径不超过100mm。

This SAE Standard specifies the essential dimensional features of HK- and HKB- half keystone rings with narrow ring width types.Dimensional and allow for the use of cast iron (table 6) or steel (table 7). Since the modulus of elasticity of steel rings is higher than that of cast iron rings, the fluctuation int he surface pressure will become greater if the free gap is set as the reference for forces. 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 half keystone rings of reciprocating internal combustion engines up to and including 70 mm diameter for cast iron rings and up to and including 100 mm diameter for steel rings.