I'm now realizing I forgot to mention that its very important for the process to accurately duplicate the hole. There will be two of these fixtures built and the holes need to yield the same result. The hole is used during the QC test and the results are dependent on it.
I'm designing a fixture for quality control and need a few precision holes. Their diameters range from 1/8" to 5/16" and need to be ±0.0002" with a depth of 1/2". I've been looking into EDM hole making and honing, but neither seem to be great for that range of diameters. Anyone know of any other...