I asked my buddy to cut a few sample holes in a scrap piece of 1/2" steel for me. I wanted him to cut two holes at .625, then a couple at .620 and .630. Then I would bring in a fixture and test the fit.
He said he cut the sample holes so I grabbed my fixture and went to his shop. For whatever reason, he either forgot or didn’t understand what I wanted but he cut 4 holes at .625 in a sample for me. They fit perfectly though so I had him skip anymore testing and just cut them all at .625. Still happy.
I asked this same question a bit ago and Jason said his tooling is undersized to fit in the .625 holes.
Here’s the thread: