down hole oil tools as parts of machines for hydrocarbon production, namely, valve balls and seats, barrels as integral component parts of pumps, valve rod guides as structural component machine part fittings used to discharge fluids, hold-down systems as an integral component part of machines composed of a one piece nipple and an inner mandrel with seals, used to release in the presence of sand and other solids so that different pumps can be installed interchangeably into the same seating nipple, insert cage systems as an integral component part of machines composed of a shell, a cobalt alloy insert that functions as a ball guide and stop, a gasket, a ball, and a connector to secure the gasket for the purpose of allowing one way flow of fluids through the cage, on-off tools for use in controlling the flow and movement of oil, pick up lifting subs, rod pump plungers, and sucker rod couplings; rod pumping systems for production of hydrocarbon comprised of valve balls and seats, barrels, valve rod guides, hold-downs, insert cages, on-off tools for use in controlling the flow and movement of oil, pick up lifting subs, rod pump plungers, and sucker rod couplings; oil field production accessories as parts of machines, namely, polished rod liners, pressure control regulators for regulating oil flow, hydraulic tubing drains for controlling oil flow, and stuffing boxes for eliminating oil spills, all used in the field of hydrocarbon production