Couplings for machines; Power-operated blowers; Self-lubricating mechanical friction parts, especially of composite materials, namely, wear rings, washers, bushings, spherical bearings, bearing pads, sliding blocks and machine transmission gears all for load bearing machines, conveyors, handling trucks and machines, lifting machines, agricultural machinery, construction equipment machines and hydraulic turbines; Machine parts, namely, roll mill bearings; Bearing inserts for machines; Machine parts, namely, bearings and bushings; Roller bearings for machines; Bearing brackets for machines; Roller conveyors