石油钻拄承受拉、压、弯、扭、剪和内、外压力的复合载荷，螺纹连接的质量直接影响钻柱的强度和密封性。为保证钻柱构件螺纹尺寸的统一，检验和校准用的螺纹量规必须具有互换性，量值必须具有溯源性。目前，我国石油用螺纹的标准主要采用美国石油协会（API）规范。在API旋转钻 Oil drill Zhu withstand pull, pressure, bending, twisting, shear and internal and external pressure of the composite load, the quality of the screw connection directly affects the drill string strength and tightness. In order to ensure the uniform thread size of drill string components, the thread gauges for inspection and calibration must be interchangeable and the values ​​must be traceable. At present, the standards of China’s petroleum threads mainly use the American Petroleum Institute (API) specifications. Rotate the drill in the API