... mining tools, welding, such as "one" bits, pillar gear drill bits, dovetail coal drill bits, drill rods riveting, all kinds of shearer, a variety ... various woodworking planer, milling, and welding a variety of woodworking drill. 2. Forging, rolling class2.1 The variety of hot- ... as high strength bolts, nuts and so on.2.3 drill steel, tempering brazing, forging, extrusion heating. 3. Heat treatment ...