A.公稱直徑為24mm,螺距為1.5mm的左旋細(xì)牙普通螺紋 B.公稱直徑為24mm,螺距為1.5mm的左旋粗牙普通螺紋 C.中經(jīng)為24mm,螺距為1.5mm的左旋細(xì)牙普通螺紋 D.小徑為24mm,螺距為1.5mm的左旋細(xì)牙普通螺紋
A.前B.后C.中D.上
A.基圓 B.大經(jīng) C.中經(jīng) D.小徑