圈上海人峰 60°4 H H H=0.866p 3.American National Standard thread 23 60° H=0.866p 内纹（螺母） 中径线 距P 蝶EP 内螺纹轴线 外螺纹线 4.Unified Standard thread 2423 3. American National Standard thread 4. Unified Standard thread 24