Bolt tightening machine is mainly used in automobile related industries, tractor agricultural machinery industry, high-speed railway/bullet train industry, wind power industry, military industry, light industry, etc. According to categories, there are three main types, respectively DDK electric servo tightening spindle, DDK handheld electric wrench and DDK electric servo press assembly machine as well which mainly uses the lightweight high speed motor and enhanced the maneuverability and the productivity. U type bolt tightening machine includes some different types and different environmental requirements can be well developed with our superior feelings and applications. Controller adopts the latest digital technology, abolished the past various structure and is equipped with a variety of communication interface and control mode to in a wide range of spares wiring operation, realize the whole network system, gluing plug cap installed it adopts electronic pulse technology not only greatly reduced the operator when tighten the reaction force and the intensity of labor, and in accordance with the requirements for posh design to protect the environment. In the category is also very diverse, timing gear press is worthy of our trust and choice.