问题
问答题
用三针测量法测量Tr40×7的米制梯形螺纹，求量针直径dD和量针测量距M。
答案
参考答案：已知d=40mm、P=7mm
dD=0.518P=0.518×7mm=3.626mm
M=dz+4.864dD-1.866P
=d-0.5P+4.864dD-1.866P
=40mm-0.5×7mm+4.864×3.626mm-1.866×7mm
=41.075mm
[答] 量针直径dD为3.626mm，量针测量距M为41.075mm。