Are they the same? Can holders be used interchangably? I see catalog listings for all three and have assumed that they were somehow enough different to not interchange, but a recent message made me doub that assumption.
I have an NMTB 30 taper on my Bridgeport with a nut to hold the holders in place (as opposed to a draw bar). Are the above answers the same if you don't use a drawbar or is one required (or recommended) with any or all of them?
From what I've seen, I think ISO30 and NMTB30 are the same. Extended boss on the end for the drawbar threads on both, nothing fancy about the flanges.
Cat30 has no extended boss on the end for the drawbar threads, since it is designed for a screw in stud for a drawbar puller to work on. This means extending your drawbar to reach the Cat30.
You might be able to use one drawbar for both, however, it would be screwing a long ways into the NMTB threads, and possibly, there might not be enough good thread depth, causing the bar to bottom out before it reaches its shoulder on the top of the spindle.
Edit: the Cat V flange is thicker than the others, so it may not work with a spindle nut on your machine.
I think the CAT 30 uses a different thread, metric, than the NMTB 30 holder english. So aside from the length of drawbar needed, the threads would be a bit different as well. Both can be used on the same machine given it's a 30 taper. You would just have to swap drawbars to do it.
I recently bought a Bridgeport/Hurco CNC knee mill with the QC 30 tooling and I love it. It came with a ton of tooling. I found a couple holders in the group that don't fit in the spindle and I believe they are CAT30. Have a look at the Parlec web site for a definitive answer, with dimensions for various tapers:
The QC (nmtb) 30 tooling is great. It's nice to be able to switch tooling quickly. I have my machine set up in the garage doing small batches of parts for a bit of money. Incorporating tool changes into the CNC programs makes life a lot easier.
Cat 30 and NMTB30 both use 1/2 x 13tpi.
Its the BT series that have metric threads [img]smile.gif[/img]
My mill had ISO 30 holders until they were stolen. I was surprised that the same drawbar works on NMTB 30 shanks.
In view of what Mr. Dung has said I will have to check that new holder.