I managed to buy six boxes of TNMP432K Kennametal tool tips in te KC850 grade carbide, these looked like too good an offer to miss, but the holders are really quite expensive for the hobbiest, also designed for almost long production runs under production shop conditions, most hobby shops I would say never get near to running production tooling anything like it is designed for, so maybe I could get away with a case hardened steel version, costing a fraction of what a commercial version would be.

  The hardest part of making the tool holder is the setting up of the correct machining angle so that the tip is presented to the work piece with the correct clearance angles, this particular type of tip has a positive rake and needs to be presented to the work at a negative angle, ie drooping down.