m30 x 3.5 tap speed?

[stovepipesteve]

material A36.
machine is a VF3,30 horse, gear driven. 50 taper.
tapping 2'' deep. The tap is 4 fluted.
im thinkn of starting out about 100-125rpm.
ill be holding the tap in a collet so im worried that it will slip in collet running the torque its going to require to tap 2'' deep.
any thoughts would be great.
thanks.

[Donkey Hotey]

Edit: I'm a moron. I read the original post as a 3.0 mm tap, 3" deep, not a 30 mm. Never mind. That's a huge tap. Ram that sucker in there.

[dertsap]

the collet will probably slip pecking or straight tapping
your best bet is to ditch the collet holder and make a sleeve to fit the tap into a sidelock ,other than that i cant see any reason you can't tap 2" deep if its spiral flute , ive done it many times with near the same or larger dia taps to more depth , chances of breaking the tap is slim to non if it is of any quality ,
if your tapping multiple holes then i would suggest monitoring the tap in between holes and watch that your not building a bird nest around the tap because it will do damage

[Jason3]

Greg - you had me worried there I thought I was a bit of a small thinker for a while - wow, I thought. M30 is a small tap. He must do some BIG work!

Jason

[Donkey Hotey]

Yeah, I was looking at some really small taps the other day. I read the post and wondered how sombody would push a 3.0 mm tap through 17D worth of steel.

[Excelmachine]

How about thread milling it?

[stovepipesteve]

well i went in for the kill today and ran the big M30x3.5, 4 flute, bottom tap 2 inches deep,3 times.
I used a speed of 120 and a feed of 16.5354. i flooded it with coolant and let her rip, it did awesome. Im holding it in a large collet so ill keep an eye on the holder cap loosening or slippage.
Thread milling was not an option due to cost and hard to find mill body to insert type and ive never thread mill before, i would love to master it though.

[ttieuli]

You can try Vardex thread mills. I've thread milled some pretty big threads with them. Vardex has software that will write code you can cut and paste.
It's really very easy!

[PBMW]

You could have bought two thread mills for the price of that tap....
And it would do the job nicer and faster. Not to mention lasting longer....

[dertsap]

Originally Posted by PBMW And it would do the job nicer and faster. Not to mention lasting longer....

nicer ?
threadmilling will take a lot longer amount of time if there are multiple holes