As I look at fractional, number, letter, and metric drill sizes, I am surprised to see that none start with 0.44 inches. I can get 0.4375 with a 7/16 which is 2.5 thou under and can get 0.4528 with an 11.5 mm which is 2.8 thou over. Funny quirk.

This gap can be filled with a homemade reamer or by grinding the 7/16 a little off center so it cuts oversized. This is not a show stopper. I also see that I can buy a commercial 0.455 drill from Granger for around $100. I don't want it THAT bad.

Just for grins, I might make a go/no go gage with 0.443 and 0.447 just in case I need to finesse a 0.445 hole someday.

Rick