Small shallow holes

Any ideas for making holes .025" diameter x .025" deep? Minimal bottom radius. I’m using Copper electrodes. Need help with my condition.

I’m assuming you are burning into toolsteel of some type with a sinker EDM.
With copper you are going to get a lot of wear.
You have a couple of options:

  1. Use copper tungsten, which will wear at a much lower rate.
  2. With copper, burn and then redress the bottom of the electrode on a piece of carbide to get it flat again. Then reburn and repeat until you get the desired result.