... 1/4’’*1/4’’6.4mm*6.4mm22,23,243/8’’*3/8’’10.6mm*10.6mm19,20,21,221/2’’*1/2 ... ’’12.7mm*12.7mm16,17,18,19,20,21,22,235/8’’*5/8 ... ’’16mm*16mm18,19,20,21,3/4’’*3/4’’19.1mm*19.1mm16,17,18,19,20,211’’*1/2 ... ’’25.4mm*12.7mm16,17,18,19,20,211-1/2’’*1-1/2’’38mm*38mm14,15, ... DiameterIn inchIn metric unit(mm) 1/2’’*1/2’’12.7mm*12.7mm16,17,18,19,20 ...