Gruntz Washer Bases

I like using zinc washers for miniature bases, to provide a magnetic connection and for the weight. However, I also like having properly sized bases with a lip. This is what I've come up with. Both bases have a hole in the bottom, large enough to fit a SAE #10 washer.

The hex base is about 30x35 mm on the bottom, and just over 25x30 mm on the top, with 4 mm thickness. The round base is 16 mm wide and 3 mm thick.