In the field of pipe and plate processing in China, due to the emergence of the back-pull crown drill, which replaces the original rocker arm drill and U-drill, and greatly increases the tolerance of the hole diameter, it brings a new development to this industry. In the past, the pipe manufacturing industry used U-drill processing, compared with the U-drill, U-drill general processing depth is limited to 5D or 6D, hole diameter tolerance in ± 0.3 or so, while our production of modular drills, processing depth can be up to 16D, hole diameter tolerance in ± 0.02, due to the replacement of our drilling inserts, but also greatly save the cost of the carbide part. The result is a highly efficient, high-precision, low-cost machining method. This greatly promotes the development of the tube and plate industry. At present, we are extending this advantageous production method to the whole world. Contribute to the world tube and plate industry.