... metric unit(mm)1/4" x 1/4"6.4mm x 6.4mm22,23,243/8" x 3/8" ... .6mm19,20,21,221/2" x 1/2"12.7mm x 12.7mm16,17,18,19,20,21,22,235/8 ... ,17,18,19,20,211" x 1/2"25.4mm x 12.7mm16,17,18,19,20,211-1/2" x ... x 38mm14,15,16,17,18,191" x 2"25.4mm x 50.8mm14,15,162" x 2"50.8mm ... inchIn metric unit(mm)1/2" x 1/2"12.7mm x 12.7mm16,17,18,19,20,213/4" x ... x 19mm16,17,18,19,20,211" x 1"25.4mm x 25.4mm15,16,17,18,19,202" x ...