A.0.86603×P B.0.57735×P C.0.3333×P D.0.7534×P
A.16.7 B.15.7 C.14.7 D.13.7公厘
A.等于節(jié)徑 B.公稱直徑-節(jié)徑 C.公稱直徑-底徑 D.公稱直徑-螺距