NMTB shank compatibility with Erickson Quick-Change Spindles:

The NMTB shank was developed for use in the NMTB spindle which uses a draw bar to pull the shank up into the spindle. Tool flange thickness, distance from the gage line of the taper to the outward face of the flange and the flange diameter are not critical dimensions when used in the NMTB spindle. As a result, these dimensions were not consistent between all manufacturers of NMTB tooling.

The Erickson Tool Company developed the Erickson Quick-Change spindle to use the NMTB 30, 40, 45 and 50 tool holders already in existence. The Erickson QC system does not use a draw bar, it uses a quarter turn "locknut" to push and hold the tool taper in the spindle. Two "lips" in the nut push against the outer face of the tool flange. The key dimension (gage distance) that causes some NMTB holders to not work in an Erickson Quick-Change spindle is the distance between the taper gage line and the outer face of the flange (gage distance = L4 + L5 in above tables). Gage distance on some NMTB holders is too large, which does not allow the "lips" in the QC nut to engage the outside face of the flange.

The other issue is that the flange diameter (D5) on some NMTB holders (mostly cheaper imports) is too large to fit in the mouth of the Erickson Quick-Change spindle nut.

All NMTB holders made by Erickson work fine (they are marked Quick-Change), all Universal Engineering holders work fine and I've read that Kennametal, Collis and Valenite holders work fine (at least the ones made in the last 20 years or so). The compatibility of other holders is in question. However, all is not lost, the flange of the tools that do not work can be ground down a small amount and then they work fine in an Erickson spindle without affecting operation in an NMTB spindle.

(See Erickson grinding procedure)

The "tail" of the NMTB shank is not required when mounting in an Erickson Quick-Change Spindle. So 30-Taper and 40-Taper tooling, without tail, work fine as long as the flange dimensions are correct. DO40 and DT50 tooling can also be used in Erickson Quick-Change spindles, but you may need to take a bit off the tail "ribs" on some tooling for clearance in the Erickson QC spindle.