Thanks again for the quick replies.

Yes, I am using a soluble oil, and have never had any issue with galling on any of my tools. 5% is the recommended mixture ratio, and I keep it very close. My tools last a really long time, at least what I think is a long time. I keep track with number of parts machined. My last 1/8" EM went a good 4 months with well over 1500 parts until it snapped running at the same DOC, plunges and loads as previously described. And I am now pretty sure it snapped because of a machine issue, not because it was worn. I lost the piece when it snapped so I couldn't check it. The final cuts before it snapped looked really good. My 1/4" and 1/2" are much older and no signs of needing new ones. I have had the same luck with other brand tools as well, not just the ones I'm using now.

I see that I may need to improve on my plunging techniques, which I will take into consideration, though I don't feel this is the issue here.

I spent some time with the Hass technician and ran a number of tests on the spindle. So far the spindle runout is perfect and right at spec at just under .0002" (measuring at about 10 spots inside the spindle). I also did the pull test where you pull on the tool holder at the collet, and it was within .0005" again right where it should be.

Next step is to test the spindle drawbar force. Now I'm stuck. Can't find a gage locally, so I need to get a service rep in and have them check it. 2 hours of driving to get to my place plus the standard service fee. Oh well. Guess I have to get it done!

The reason I feel it may be something in this area is because I can take a number of tool holders, stick them in the spindle, measure the runout in the collet seat, which has been around .0008" or worse and way out of spec. Then remove the tool, and stick it right back in again, and it will change up to .0015" of runout. I can go in and out with the tool holder keeping everything else consistent (table not moving, indicator not moving, just the Z axis going up and down and always to the exact Z height as before.) and the reading will vary on the same tool holder.

I did spend some time cleaning and polishing the spindle just to make sure I couldn't find anything obvious in there.

When I checked the runout of my tool holders yesterday, I found one that seemed to be a little better than the others. So I actually took my 1/8" EM and stuck it into this holder. This definitely made a difference on the cut. So I know I'm going in the right direction and my issues are with excessive runout.

The Haas tech also said all the runout measurements I was taking on the tool holders was some what invalid until I get the drawbar pressure checked, which makes sense. If the tool is not going up all the way, I will get a different reading.

But maybe that one tool holder was newer than the rest and happened to seat a little better? Who knows, just guessing right now.

Thanks again and I'll post back what I find out in hopes it helps other users in the future.