Shawn
That sounds more like a #30 taper
From the Machinery handbook for the NMTB style, length may be
different for pullstud type holder. but the taper and gage dia will be
standard.

gage dia 1.25
spindle dia 2.749
pilot dia 0.690
length 2.88
taper 3.500/ft

Shawn Edward wrote:
Hello all,

A friend of mine picked up a Model 36 Diamond Universal Milling
machine from army surplus. The vertical mill is incomplete, but the
horz. section is complete and works. I've been helping him track down
some information on it, mostly about the Horz. taper to find tooling.

Here is some measurements about the horz taper:

Cone Diameter Base: 1.238in
Cone Diameter Top: .639in
Cone Height: 2.142

Base Thickness: .449in
Base Diameter: 2.675in

He is thinks that it might be a bt40 or bt50, but is not sure. Any
help or pointers would be appreciated.

Shawn Edward