[Ed Caffrey]

As Erik said..... washers are usually NOT recessed. Their main purpose is to create space between liners and the blade.

Bearings are recessed, either in the liners or the blade. This is best accomplished with with a piloted counter bore.
Using an end mill is a hit and miss affair....more often then not, an end mill will "walk" slightly, creating an oval instead of a round recess. Finding the correct size counterbore can be a challenge. I use the ones with interchangable pilots, and purchase them from MSC supply or from specialty sources..... in the past I have had such a difficult time finding what I needed, that I actually had some carbide counterbores made to my specifications...... but they were very expensive.