7 Bearings [parts of machines]; bearings, namely, roller bearings, spherical plain bearings, ball bearings, self-oiling bearings, anti-friction bearings, engine bearings, precision bearings and bearings for transmission shafts, being parts of machines; machine parts, namely, bearing housings, bearing brackets, bushings, pulleys, tensioner and idler pulleys, sprockets, mechanical seals, universal joints [Cardan joints] and couplings; crankshafts; power transmission chains and belts not for land vehicles; conveyor chains; belts for machines, motors and engines; fan belts for motors and engines; sparking plugs for internal combustion engines; glow plugs for diesel engines