To help with the amount of questions I get daily regarding which bit to use and what bits I have in my range, I have developed a Guidalogue... a what? That's right, a guide built into a catalogue to give you as much information to get you going.
Check it out here Guidalogue
Just a reminder that all machines are not made equal. Each CNC has it's limits and therefore you must choose your bit sizes accordingly.
Max bit cutting diameter size per machine
3018 / 3018 Pro - 2mm optimal - 3.175mm upper limit
X-Carve / 3DTek XYZ-Carve / BlueCarve Bluey / Beige 6040 / Youcarve - 3.175mm optimal - 6mm upper limit
BlueCarve Turbo / 3Dtek Heavy Mill / WorkBee / LeadCNC / QueenBee - 8mm upper limit