节距范围大于20，最大直径节距为200的齿轮。标准音高；两个基本齿条（一个带有齿隙余量）；修改齿顶和中心距以适应各种条件。四级精度，基本和双面复合测试公差。附录:单侧面试验、测量销尺寸计算、各种设计条件的计算。交叉引用:BS 978:第2BS 978部分:第3BS 978部分:第5PD 3376部分取代BS 978:第1:1962部分。

Gears of pitch range greater than 20, up to 200 diametral pitch. Standard pitches; two basic racks (one with backlash allowance); modification of addendum and centre distance to suit various conditions. Four grades of accuracy with elemental and dual flank composite test tolerances. Appendices: single flank testing, calculation of measuring pin dimensions, calculations for various design conditions.Cross References:BS 978:Part 2BS 978:Part 3BS 978:Part 5PD 3376Replaces BS 978:Part 1:1962.