I almost wrote"Elton" (Rocketman)! The Cutters I make out of "O1' are Straight sided, on the Inside,giving a "Cut' that is aprox. .020 thou. The 2nd tool is my Carbide 90* I have about 7 or 8 of them,from the 1st one I brought from 'Direon???1986......The old one's are good for The 1st Run-Thru....If I can dig up some of my Technicana Photos I'll ask BLH to post them..CC/DT