During drilling, first under the WOB, located in the bottom of the pivot tube teeth at the bottom center of the Centre "cutting", forming broken free surface located on the spiral bevel cutting with follow up, form a cone drill, drilling bit teeth form a line at the end of the hole is the projection of a series of concentric circles. Rock chip and soil, such as along the helical blade back up, after full between the blades, drill out of the hole, or after falling into the hole, sand bucket bails out.
Short Auger drill bits parameters pitch, Helix length, cone angle of spiral drills, cutting with cloth teeth spacing, cutting tool cutter diameter Helix angle, tooth angles and length of bit teeth, alloy head and so on.
Single screw spiral drill cutters short single-cone is relatively small, typically cemented into a loose gravel, especially much larger formations of cobble and gravel and weathered rock. Due to the large single bevel single bit of spacing between blades, drill cuttings, clods and debris falling in the Jack, you need to use a sand bucket to sand the end of Qing dynasty, is generally a drill Auger, drill a sand bucket drill, alternately. Many Auger is broken or blended porous cemented weathered layer or gravel at the end of the function.
Short double conical twin screw Auger is biconical cutters, cutter number one single screw short spiral cone bit 1.5~2 times, generally fit into the weathered rocks and gravel and small gravel. Drilling is double drilled teeth in the same time, high efficiency drilling, drilling more stable.