Re: [CAD_CAM_EDM_DRO] Re: Thread milling

R Rogers wrote:

> The original poster indicated that "standard" collets have a range of acceptability in regards to diameter.

I might have missed that, but then what "standard" are we talking about?
5C, R8? Certainly, no argument there. But DA and ER collets
are "standard" too, and they don't care if they are holding a tap by the
shank, or a drill.

Your assersion tap shanks are not for chucking makes me wonder if you've
ever worked in a real production shop. I have two Procunier tapping
heads that most certainly grip taps by the shank. Yes, they're ground to
fit the taps. But the appropriate size DA or ER collet will conform to
the very same tap shank and grip it just fine, for the purpose of thread
milling. And I've seen several large CNC shops that rigid tap holding
taps in ER collet holders. Lets also not forget Morse split tap holders
which also grip the shank.

IF the OP referred to holding taps in spindle collets you are correct.
But you lump all collets into this catogory, and there you're wrong.
Your choice if you want to be a 'purist' and limit your options, but you
make blanket statements that might keep others from trying an approach
that might solve a problem for them. And that's why I'm going to risk
drawing the OT stamp this thread is sure to soon get, hate to see a post
discounting alternatives as the last word on the subject.

Anyone wanting to discuss this further, Jobshophomeshop is the
appropriate forum. Might be interesting to learn how many folks hold
taps in collets...

Jon