Granted Patent
Utility
US 5,580,398 · App. 08/244,123
Method of forming passive oxide film based on chromium oxide, and stainless steel
Inventor:
Tadahiro Ohmi
Patented Case
View Patent ↗
Granted: Dec 3, 1996
Filed: May 19, 1994
Inventor
Tadahiro Ohmi
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.