NZG-31 Rail Drilling Machine NZG-31 rail drilling machine is compact in structure, and it is the lightest drilling machine in China at present. The rail clamping device has self-locking function, accurate positioning and high drilling accuracy. The n-tailed hollow drill bit can be used to clamp the special twist drill with n-tailed shank under 13.5 according to the needs. It has the function of automatic water supply when drilling. It is a necessary tool for maintenance, rush repair and overhaul operation of Public Works Department. Advantage 1. The water supply at the back of the main shaft is adopted to prevent the cooling water from entering the bearing and reducer, so as to improve the service life of the equipment. 2. When drilling, the rotary resistance is reduced and the drilling torque is increased. 3. The drilling time is shortened and the production efficiency is improved.