Single Flare > 10 gauge ~ 2.5mm > 6 gauge ~ 4mm > 4 gauge ~ 5mm > 2 gauge ~ 6mm > 0 gauge ~ 8mm > 3/4 inch ~ 19mm > 1-1/8 inch ~ 28.5mm > 1-1/4 inch ~ 32mm > 1-1/2 inch ~ 38mm > 1-3/4 inch ~ 44.5mm