Ключевые слова: abstract, background, bolt, brass, bush, bushing, connector, copper, different, equipment, external, female, fitting, group, head, hexagonal, inner, internal, iron, isolated, jack, lot, male, many, mechanical, metal, nobody, nut, part, pattern, piece, pipe, plug, plumbing, repair, ring, screw, service, sleeve, spare, steel, stud, supply, technology, thread, tool, tube, union, white,