Granted Patent
Utility
US 4,959,331 · App. 07/266,721
Alumina-zirconia-silicon carbide-magnesia cutting tools
Inventors:
Pankaj K. Mehrotra, Elizabeth R. Billman
Patented Case
View Patent ↗
Granted: Sep 25, 1990
Filed: Nov 3, 1988
Inventors
Pankaj K. Mehrotra
Elizabeth R. Billman
Assignee (at issue)
KENNAMETAL INC.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.