M2.5 X 0.45 6H TAP RPM

[surfit]

I have to tap M2.5 X 0.45 6H x 6MM Deep blind hole and I only have 1 tap. It's not really right for this job it is a four straight flute type, I have some spiral flute taps comming next week. The material is 6061-T6. Machine is a Hatachi Seiki mini center mill 30 taper. I am thinking 1000 rpm any suggestions?
Thanks

[fizzissist]

I wouldn't run it that fast. 300rpm maybe... Not because the SFM is too high, but heat transfer issues and the 4 straight flutes..sounds like a "hand tap"??
I hate those #@$! things.

Push the tap drill diameter to the largest drill that gives you an in-tolerance hole, after spot drilling, and make sure you're clearing chips. That material taps very easily.

With good quality spiral flute taps 1000rpm should be easy...and while 6mm is 2 1/2 diameters, it shouldn't be a problem...and especially if you get taps that are are relieved.

Another thing to consider if you're machine will repeat the lead, is to do 2 passes, the second one to depth after clearing chips from the first.