A.(0.1~0.3)軸頸直徑 B.(0.01~0.03)軸頸直徑 C.(0.001~0.003)軸頸直徑 D.(0.0001~0.0003)軸頸直徑
A.1 B.2 C.3 D.4
A.大徑 B.小徑 C.大徑和小徑 D.齒側