Process of manufacturing drill stems for deep-well drill rods from non-magnetizable austenitic manganese-chromium alloy steels

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

• Granted April 14, 1964. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 14, 1981.
• We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.