Single Flare > 12 gauge ~ 2.0mm > 8 gauge - 3mm > 4 gauge ~ 5mm > 2 gauge ~ 6mm > 0 gauge ~ 8mm > 1/2 inch ~ 12.5mm > 5/8 inch ~ 16mm > 3/4 inch ~ 19mm > 1-7/8 inch ~ 48mm