The diffusers are a pain to get out. Took me a few hours with a fresh carbide.

I originally tried to cut them out with a sawzall blade. That didn't work, so I went at it with a carbide and it was also messy.

 

Use a grinding stone on the diffusers. Takes under 10 minutes per side. Less of a pain in the *** than finding and installing TII sleeves.

 

One can saw Inconel with a HSS blade. It just has a very low cutting speed, the same would apply to a carbide burr but not to the same degree. I'd use 1/4 speed of what works good for just plain steel as a starting point.

 

What about pressure, compared to mild steel?

 

Lots of pressure, slow speed. Carbide burr, not so much on the pressure, the little teeth are only so strong. HSS is actually stronger than carbide. Just tone the speed down and one should see better results. Inconel is very tough and work hardens. It just plain sucks to machine, it really does.