(1) High Production Efficiency. Broaches are multi-tooth cutting tools, with a large number of teeth working simultaneously, increasing the total cutting width. Furthermore, a single stroke of the broach can complete roughing, semi-finishing, and finishing processes, significantly reducing basic processing time and auxiliary time, thus resulting in high production efficiency.
(2) Wide Machining Range. Broaching can machine not only flat surfaces and unobstructed external surfaces but also through holes of various shapes, thus offering a wide machining range.
(3) High Machining Accuracy and Low Surface Roughness. Broaches have a calibration section for calibrating dimensions and adjusting finishing. Additionally, the cutting speed of broaching is generally low (<18 m/min), and the cutting thickness of each cutting tooth is small, resulting in a smoother cutting process and avoiding the adverse effects of edge formation. Therefore, broaching can achieve high accuracy and low surface roughness. Generally, the dimensional accuracy tolerance grade of broached holes is IT7～IT8, and the surface roughness Ra is 0.4～0.8μm.
(4) Simple Structure of Broaching Machines. Broaching involves only one main motion: the linear motion of the broach. The feed motion is achieved by the subsequent tooth of the broach rising higher than the preceding tooth. This rise is called tooth lift. Therefore, broaching machines have a simple structure and are easy to operate.
(5) Long service life of broaches. Broaching involves lower cutting speeds and slower tool wear. A single sharpening operation can process thousands of workpieces, and a broach can be re-sharpened multiple times, resulting in a long service life.
While broaching has these advantages, its structure is more complex than that of general hole-making tools, making manufacturing difficult and costly. Therefore, it is only suitable for batch and mass production. In single-piece and small-batch production, broaching is sometimes used for certain high-precision, specially shaped surfaces that are difficult to machine using other methods. Blind holes, deep holes, stepped holes, and obstructed external surfaces cannot be machined using broaching.
