Knowledge of operating principles, purpose, proper application, and design limitations of mechanical and hydraulic power transmission components or elements such as shafts, bearings, gears, pulleys, belts, chains, seals, fasteners, couplings, brakes, clutches, pumps, valves and similar devices. Knowledge of operating principles, purpose, proper application, and design limitation of tools, equipment, and devices used in the moving and installation of machineries such as hoists, cranes, lift trucks, dollies, rollers, jacks, welding and cutting equipment and a variety of hand tools.