AA、A、B和D四个等级的尺寸和允许误差。平行滚刀杆直径，锥形滚刀杆的尺寸。交叉引用:BS 350BS 436BS 2519BS 2062:第2ISO/R 53ISO/R 54部分被BS 5221:1975取代，但在就公差达成国际协议之前，该标准仍然有效。包含以下内容:1960年12月15日出版的PD 4015

Dimensions, permissible errors for four grades AA, A, B and D. Parallel hob arbor diameters, dimensions of hobs for taper arbors.Cross References:BS 350BS 436BS 2519BS 2062:Part 2ISO/R 53ISO/R 54Replaced by BS 5221:1975, but remains current until international agreement is reached on tolerances.Incorporates the following:PD 4015 published 15 December 1960