front wheel bearing size question

Hey guys, i'm looking for the size of the outer "hole" of the wheel "knuckle" for the wheel bearing ( mazda3 2.0L). I'm gonna replace a front bearing on the car this weekend and I wanted to machine a steel cylinder to push the old 1 out with a press. I did some search on the forums but couldn't find the information I wanted.

If anyone know it, I'd love to hear about it, it would save me a bicycle ride from the house back to the shop :P

here is a pic of the size I'd like to know (this isnt a mazda 3 part, its just some random knuckle i found from a google search)

https://imgur.com/kLTsA4a

Thanks!

Mel