Having a failure in using carbide drill bits through hardened steel, I ordered a nice Bosch cobalt drill set to try next. The first shot at it, duplicating the approach with the carbide, ended the same way. It drilled partially through, then stopped. Then I followed the advice of a viewer ( @billschiff2060 ) with additional info from another YouTuber ( @BenOrford ) , today was a success. I'm not sure if the modified approach might have worked with the carbide bits, but as I haven't tested it, I'm not sure. I plan to do that tomorrow, and satisfy the curiosity.