I am in search of a flat head machine screws with an 82 degree countersink that have 1/4-20 UNC thread, but have a countersunk head that is characteristic of a 5/16-18 standard screw. That is, I want a standard machine screw with an oversized head.
I have been trying to search for these, but no search term I've tried works. If such a fastener existed, what would it be called? Can anyone confirm that they do or do not exist commercially?
(I know of course that I could fabricate them, but for a number of reasons, that's not desirable.)