Yes 3D printing can do some pretty cool things, but if you need more than 20, you might as well machine them.
Below is another project I just completed for someone that went down this path. You can also get some more exotic finishes ranging from Teflon to etches. Right now it's nifty, and may work for prototyping, but not practical for manufacturing.
I've been watching this field closely, and at some point it may, but right now not so much.