Single Flare > 12 gauge ~ 2.0mm > 6 gauge ~ 4mm > 2 gauge ~ 6mm > 0 gauge ~ 8mm > 00 gauge ~ 9.5mm > 7/16 inch ~ 11mm > 1/2 inch ~ 12.5mm > 1-5/8 inch ~ 41mm > 1-3/4 inch ~ 44.5mm