View Full Version : 40 taper

charlie coghill
03-11-2005, 11:53 PM
Hi All.
I have a nichols Horizontal miller with a 40NMTB taper. The question is, are other 40 tapers the same, such as a CAT40? I have seen other 40 tapers listed on E-bay that have some letters befor the 40. I don't have a clue as to wheather they will fit the 40NMTB. http://bbs.homeshopmachinist.net//confused.gif

Thanks for any enlightment that you fellows can give me.

03-12-2005, 01:38 AM
Hi Charlie,
All the "40" tapers are the same as far as the taper 3-1/2" taper per foot, the size of the large end of the tapers is with in a couple of thou. of each other. The main difference is the holding of the tool holder, on a NMTB 40 holder there is a straight portion at the small end of the taper, for your NMTB 40 holder it is tapped 5/8" N.C. The equivalent European taper (BT40)is tapped 16m/m x 2P. The ones you are seeing on Ebay are CAT40, CT40 these are also tapped 5/8" N.C., BUT the straight portion at the small end is missing. You can still use these holders if you make a longer draw in bar with 5/8 N.C. If you pick up a BT40 holder the end of the draw bar would have to be threaded 16m/m x 2P. The CAT40,CT40,BT40 all have a "V" groove on the drive flange, this is so they can be held in an automatic tool changer system, these use a pull stud or a retension knob that pulls the holder into the spindle, but these pull studs or retension knobs are threaded 5/8" N.C. of 16m/m x 2P, they still have the 2 drive key ways just like the NMTB40 holders.
I hope this helps


Forrest Addy
03-12-2005, 01:47 AM
Yup. As Vmil says. All you need is three draw bars.

Well, two drawbars: one can be the equivalent of a hunk of all thread that with a free running nut will work for 40 NMT and CAT 40 tapers.

03-12-2005, 08:25 AM
THATS HOW I did it on my cinn #1, got most tools off ebay for $10 to $50 each. used allthread for drawbars.

charlie coghill
03-12-2005, 10:42 PM
Ok guys thanks a lot. I am in tall clover now http://bbs.homeshopmachinist.net//biggrin.gif and can start acquiring some tooling.

03-13-2005, 12:39 AM
Be careful you don't wind up with a holder that has an integral retention knob - don't just assume they unscrew and give you a 5/8-11 threaded hole.

Also while they have the two drive keys one slot is not as wide in the CAT40 holders, so you'll need to remove one of the keys from your spindle nose. Not a big deal, but with all the stuff on ebay, it shouldn't be hard to find exactly what you want in actual NMTB40.

It has been 6 years since I bought any, but at that time I didn't like any of the far-east imports. There seem to be plenty of new ETM (Israel) and Kennametal NMTB40 holders around at reasonable prices.


03-13-2005, 11:34 AM
I bought some cat 40 stuff and made some adapters so they ran 5/8-11 like the NT40 stuff I have,uses the same drawbar that way.

charlie coghill
03-13-2005, 10:47 PM
Thanks Tool and Weird.
This machine has a grove in the spindle for a positive drive already.

I don't too many tools for this mill but do want more than the mandural.