The threaded rod diameter refers to the diameter of the external threaded surface.
The main geometric parameters of cylindrical thread:
①Outer diameter (major diameter), the diameter of an imaginary cylinder that coincides with the crest of the external thread or the bottom of the internal thread. The nominal diameter of the thread is the major diameter.
②Inner diameter (small diameter), the diameter of an imaginary cylinder that coincides with the bottom of the external thread or the top of the internal thread.
③Pitch diameter, the bus bar passes through the imaginary cylinder diameter with the same width as the protrusion and groove on the tooth profile.
④Pitch, the axial distance between adjacent teeth on the pitch line corresponding to two points.
⑤Lead, the axial distance between two points on the pitch line of adjacent teeth on the same spiral line.
⑥ Thread angle, the included angle between two adjacent flanks on the thread profile.
⑦ Thread lift angle, the included angle between the tangent of the spiral line on the pitch cylinder and the plane perpendicular to the thread axis.