Drilling equipment, namely, drilling machines and parts therefor, namely, torque converters, kelly spinners, pipe spinners, air compressors, wireline machines, air hoists, winches, air starters, motors, gas compressors, mud agitators, desilters, desanders, centrifugal pumps, shale shakers, drawworks, substructures, and derricks, and service manuals therefor sold as a unit with the foregoing