Cut hardened metal

[toplessHO]

Ive got a gear that I need to bore out approximately 3mm,from 22mm to 28 mm diameter.
Finish doesnt need to be super smooth as it will get a press fit sleeve,however it must be concentric
and centered.
What will work? Waterjet,laser,edm?I have no idea of the hardness.

 

[bsaint]

Most likely only the teeth are hard. A lathe is probably the best choice. Laser forget it. Waterjet is good but those guys don't know how to center it concentrically. Edm would be cool but still not the same. Oh man someone should make an edm lathe.

 

[Dumber than lumber]

Why wouldn't you just take it to a machine shop?

 

[toplessHO]

Most likely only the teeth are hard. A lathe is probably the best choice. Laser forget it. Waterjet is good but those guys don't know how to center it concentrically. Edm would be cool but still not the same. Oh man someone should make an edm lathe.

yes that is assuming the race is hardened because its riding on a hardened shaft

 

[bsaint]

The shaft would be harder. Imo if I was engineering it. It rides on oil so like babbet bearings, it doesn't need to be hard.

 

[bsaint]

I was just thinking tho if you are right and the ID is hardened, it might only be case hardened instead of through hardened. Then once you increase the ID bore, you're going to have to re hardened the bore to the original spec.

 

[speed bump]

Lathe would be the easiest. Drill press and a reamer to finish would be the most available tooling.

I'm going to bet it's not hardened.

 

[The Cobbler]

lathe can turn some pretty hard stuff, I would look at boring it in a lathe

 

[gorilla]

test the bore with a file that will tell you if it's hard. Even if it's hard you can try to bore it with a carbide boring tool might work part looks like junk so not much lost if you mess it up. Some shops can do internal grinding but it's costly.