... -750mm 3. Pitch :800-30mm 4. Thickness :2-8mm Ground drill model :60×25×80,80×25×80,100×25×80 ... ×48×230,300×60×280Drill bit typer :twist drill ,auger drill,wedge-shape prismathic drill .Installation of the spiral blade :single spiral blade ... detector, fish on winter ice by drilling holes, etc. Ground drill bit