I frequently tap 4-40 holes in 6061 and am exploring the possibility of using a floating tap holder in our ycm-60. Usually I just use an enco auto reversing tap head in a manual mill, but I have around 200 holes to tap and am wondering if using a floating holder would be a better setup. I am having trouble finding a really good tap holder that will work in Aluminum. I have purchased some spiral flute taps and hope that I can make a go at this project with some efficiency. Does anyone have any experience with floating holders, or with tapping this small on a machine?

Thank you.:)

I see no problem with the floating holder as long as it can respond to the small thread. Some holders may be too stiff for that size tap. In such a case you are better with rigid tapping and a collet.

Can you thread form the holes instead? I have production jump what I thread form 4-40 in 6061, and I replace my thread former every 1500 holes.

You might try a thread forming tap.
The results of thread forming would probably be better for that size tap and you should be able to tap all the holes with one tap.

oops lars beat me.
But yeah...forming is the way for that thread in alluminum.

If time is what you want to save= $$$$. Then I suggest you get a drill/tap from MSC and do both in one shot.

I tap 0-80 on a Haas VF3 :D In actual fact, a cnc is a good way to not break delicate taps. I use rigid tapping now, of course.

However, before that, I used ER16 floating tapping heads for thousands of holes, most from 0-80 to 6-32, on older Bandit style controllers. Really had no problems doing it. However, the light springs in the ER floating holder might make form tapping unreliable. I never did form tapping back then, but it takes a little bit more jam to make the form tap bite and start, and I do not know how consistent that would be from hole to hole. In blind hole tapping, one thing you want, is extreme consistency in tool performance. ;).

I think your better off with the Rigid Tapping as well, but if your CNC isn't equipped with that option the Floating Holder should do fine as long as it isn't blind hole tapping. There could be some inconsistencies in the depths and number of threads.
:D

in my opinion the only real need for floating holders is on a sloppy machine , people neglect the fact most machines can run 5 decimal points ,and in a tapping cycle it is essential to keep that tap where it's supposed to be , a few points of a tenth doesn t sound like much until you multiply it by the number of revolutions the tap is turning till it reaches the bottom of the hole ,which creates added pressure to an already fragile tool

Going by Petreij's signature, I suspect the old Bandit IV is incapable of rigid tapping.

in my opinion the only real need for floating holders is on a sloppy machine , people neglect the fact most machines can run 5 decimal points ,and in a tapping cycle it is essential to keep that tap where it's supposed to be , a few points of a tenth doesn t sound like much until you multiply it by the number of revolutions the tap is turning till it reaches the bottom of the hole ,which creates added pressure to an already fragile tool

This is why I like Lathes for Threading. If you use "E" instead of "F" for your Feed Rate you can have 6 Decimal Places. This is for Fanuc and Yasnac Controls. I wish Mills were the same.