Single Flare > 10 gauge ~ 2.5mm > 6 gauge ~ 4mm > 4 gauge ~ 5mm > 2 gauge ~ 6mm > 1 gauge ~ 7mm > 0 gauge ~ 8mm > 13/16 inch ~ 20mm > 7/8 inch ~ 22mm > 1 inch ~ 25mm > 1-1/4 inch ~ 32mm