苏联乌克兰科学院超硬材料研究所及高尔基汽车制造厂采用负前角硬质合金滚刀加工未淬火的钢齿轮和花键轴。利用这种滚刀时必须修正刀齿前面的角度尺寸和线尺寸。包络表面运动理论的某些原理和方法用于设计直槽负前角梯形花键滚刀,可以简化滚刀 Soviet Union Institute of Superhard Materials, Ukrainian Academy of Sciences and Gorky Automotive Factory use unanodized carbide hobs to machine unannealed steel gears and spline shafts. The use of such a hob must be corrected in front of the tooth angle size and line size. Some Principles and Methods of Enveloping Surface Movement Theory Used to Design Trapezoidal Spline Hobs with Straight Flutes and Negative Clearances, to Simplify the Hob