Press Fit Pressure
Press fit could be a good solution , but you may take some things in consideration.
Press fit is not a hermetic seal , so if you use it at a medical device it will take by capilarity the liquid involved , and it will be so hard to it take off .
Press fit will need closer tolerances , it are expensive.
You better think in a solder , brazing or best welding .
I guess the material is ssteel so a tig welding shall be your solution.
Hope it help you.