Ключевые слова: alloy, background, bit, bits, bore, borer, boring, clear, coal, coalmine, cone, construction, cutter, cutting, damaged, drill, equipment, exploration, gas, hard, head, historic, hole, industrial, industry, instrument, iron, isolated, machine, mechanical, metal, milling, mine, mining, oil, old, part, rig, rust, scooter, section, seismic, skirt, teeth, tool, triplet, tunnel, turning, white,