... inch In metric unit(mm) 1/4x 1/46.4mm x 6.4mm 22,23,24 3/8x 3/810.6mm ... 6mm 19,20,21,22 1/2x 1/212.7mm x 12.7mm 16,17,18,19,20,21,22, ... 23 5/8x 5/816mm x 16mm 18,19,20,21, 3/4x 3/419. ... 16,17,18,19,20,21 1x 1/225.4mm x 12.7mm 16,17,18,19,20,21 1- ... 1/2x 1-1/238mm x 38mm 14,15,16,17,18,19 1x 225.4mm x 50.8mm 14,15,16 2x ... 250.8mm x 50.8mm 12,13,14,15,16 ...