Frank,
I ordered bearings from Jantz but they didn't have the counter bores in stock so I got some from MSC.
After getting everything I need and getting set up to make knives with bearings and seeing the extra time and expense to do this I'm questioning whether or not it is worth it. I know it dosent make a better knife but it is a gadget that people like and so there is a demand for it. I believe that the knife is probably weaker in the pivot because of the material that must be milled away to make room for the bearings.
I'm not condemning folders with bearings,I have come to the conclusion that they are not necessary,they do not make the knife better and believe that they make the knife weaker overall and do not wish to spend the extra time and expense to make knives with bearings.
Do not let me discourage you from pursuing this type of construction. Do it and draw your own conclusions.
Calvin