Hello, thanks for your reply.

Of course heating the hole is a method to insert a bearing and slight hammering is practical as well, that's two methods which are known.

The question was more about the possible accuracy to achieve with end mills and what's the best approach. I've read tons of threads on several forums and people mention circular interpolation is known to not be the best for precise holes. However, it's the easiest way I can think of. In fact, it is only recently that I built the CNC machine. Before that we've worked on manual machines and making a precise hole was a big challenge with special heads for boring.

I believe it is a question of tests to see what's possible and what's not for my case.