Drill bit type: twist drill, auger drill, wedge-shape prismatic drill. nstallation of the spiral blade: signle spiral blade , double spiral blade, half-duplex spiral blade. Ground drill model: ￠60×￠25×80, ￠80×￠25×80, ￠100×￠5×80, ￠150×￠28×130, ￠200×￠38×180, ￠250×￠48×230, ￠300×￠60×280