The difference between internal thread and external thread:

The joints with internal threads are called Female joints, and those with external threads are called male joints.
1. Thread refers to a spiral-shaped continuous convex part with a specific cross-section made on the surface of a cylindrical or conical matrix. Thread is divided into cylindrical thread and conical thread according to the shape of the parent body; it is divided into external thread and internal thread according to its position in the parent body, and divided into triangular thread, rectangular thread, trapezoidal thread, and sawtooth thread according to its cross-sectional shape (tooth shape) And other special-shaped threads.
2. One end is internal thread, the other end is external thread joint, including hydraulic pipe joints, socket pipe fittings, quick-change joints, method flanges, round flanges, SAE flanges, oil circuit blocks, hose assemblies, hard Pipe assembly, SB hand pump.