Would it be possible to add a calculator for feeds and speeds to use for both hss and carbide single, and multiple flutes of countersinks for a given diameter? The company I work for defaults to 250 rpm at a feedrate of 2.5 ipm for all countersinks and I am sure the smaller diameters can go considerably faster and the larger ones probably need to go slower. It also depends on how deep the overall cut is going like chamfering for a tap is no where near as strenuous as going full depth for an 82 or 90 degree flat head bolt. Maybe it could also include a depth Calc as well? How do you go about figuring this manually? I appreciate any help you can give me! Thanks Brian