Your OP is lacking a lot essential information, like all tolerances, number of holes, blind or through holes, and edge radius
A little more information might get a more complete answer.
Here are two approaches to produce smooth holes with high precision.
Use a rigided setup with sharp drill bits recommended for your material and hole size. After the hole is drilled slightly undersized you can use a round broach and burnishing tool to size and improved the surface finish. Another approach would be to use Ballizing to achieve the required finish and size.
What unclesyd said. Though, if the roughness requirement is really only required to be met in a circular lay direction, a multi-flute reamer might get you there. And if precision cylindricity is not a requirement, a brush hone can improve just about any hole finish.
it is a bushing, 22 mm total length,roughness is required in both ends (5.6 mm) we we'll use a CNC machine, in this case diameter tolerance is 3.5 mm -0.02 - 0.04, 1mio pcs per year, concentricity 0.05 mm, I was looking for a burnishing roller tool but the minimum size I found was 5 mm,
I would like to offer a suggestion about an inexpensive process for the production of your bushings. I would give the MicroGroup a call about getting precision tubing cut to length. They can make burr free cuts with very good precision. You could also buy the proper tubing and cut it yourself.
They also have Nylon/Abrasive tube brushes that maybe able to finish the part if you go the drilling route.
I've used Micro Group numerous times but there are others that cut to length.
