drilling nitronic 60 and holding .00t tp

[MPI chris]

We've got a haas vf3ss with a probing set up and were trying to drill 4 holes with a .177 osg powdered metal drill and hold .005 true position. We get closer without spot drilling This is very innacurate so we have to drill them undersized and go back and cut them in and that gets us within .001-.002 but it takes forever any recomendations on tooling and feed and speeds?

[Metalmanti]

I believe that the Nitronic 60 is a nitrogen enriched stainless and cuts similar to 316 and duplex 2101. So use similar feeds and speeds.
Try using a solid carbide drill from Kennemetal or Sandvik or anyone else. I prefer the Kenemetal. Through the tool coolant will help out a lot if you have it.
Dont use a center drill.
Feed the drill at half the feed rate till you get to the full diameter and then let'er rip. This produces a very nice hole (tight tolerance) and should be able to hold your .005 TP with no problem. You should be able to hold a +.001" diameter hole no problem as well maybe even better.

One thing to keep in mind is a rigid set up and very little to no runout of the drill in the collet.

Here is what I would run in a Kennemetal drill for your application:
4.5mm diameter B210A04500HP
180 sfm
.005 IPR (feed at .0025 till full diameter of the drill is in the part)

I am not a Kennemetal rep, just had good luck with them.

Hope that helps.
Scott