7 Machine tools, namely, power operated downhole tools used for the drilling of oil and gas, namely power operated drill bits, reamers, cutters, junk subs and debris catchers; apparatus for use in the cleaning of oil wells including the cleaning of casing strings, liners and other well tubing, namely power operated wipers, scrapers, brush tools; power operated polishers and scourers for maintaining a clean interior of a casing or liner within a well bore; power operated well clean up tools, namely circulation tools in the nature of shoes, drill bits and reamers having means for circulating fluids; power operated casing scrapers and brushes, replacement parts therefor