Does anyone have any machine time with Koolcarb Straight Flute Coolant fed drills? I am starting a new job that has (3) .625 dia holes 4.25 deep and I have been using the straight flute Koolcarb drills and I am thinking about changing to the spiral flute coolant fed drills. Does anyone have any opionions on that. Oh ya it is 6061-T6 aluminum.