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Hardening process for high speed steel tools and other articles

US 2,142,139 A · Inventors: MACHLET ADOLPH W

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3 drawing sheets

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Listed from its USPTO record in Patent Yard's full-term archive. Its claims, description and drawings are in the USPTO PDF and on Google Patents, and the Claude kit works from them.

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Why it's free to use

  • Granted January 3, 1939. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by January 3, 1956.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledJuly 18, 1935
GrantedJanuary 3, 1939
Term endedJanuary 3, 1956
Application number—
Classification (CPC)B03C3/14
Length9 pages

Sources & verification

Official USPTO records

Full published documentText and every drawing sheet as a PDF.USPTOFile historyStatus, office actions, notices, fee records and petitions.USPTO Patent CenterPatent Public Search recordSearchable full text and bibliographic data.USPTO

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