Conversion table: inch to mm

Inch mm Inch mm Inch mm Inch mm
1/16" 1,5875 5/16" 7,9375 9/16" 14,2875 13/16" 20,6375
1/8" 3,1750 3/8" 9,5250 5/8" 15,875 7/8" 22,225
3/16" 4,7225 7/16" 11,1125 11/16" 17,4625 15/16" 23,8125
1/4" 6,35 1/2" 12,7 3/4" 19,05 1" 25,40

Conversion table: nominal diameters

Int. in English inch mm EXT INT Int. in English inch mm EXT INT Int. in English inch mm EXT INT Int. in English inch mm EXT INT
1/8" 10 5 1" 34 26 2" 1/2 76 66 4" 1/2 127 114
1/4" 13 8 1" 1/4 42 33 2" 3/4 82 72 5 " 140 127
3/8" 17 12 1" 1/2 49 40 3" 90 80 5" 1/2 152 140
1/2" 21 15 2 " 60 50 3" 1/2 102 90 6 " 165 152
3/4" 27 20 2" 1/4 70 60 4" 114 102

Conversion table: Gas thread designations

Nominal in inches Common designation Theoretical" outside thread
1/8 5 x 10 9,72
1/4 8 x 13 13,15
3/8 12 x 17 16,66
1/2 15 x 21 20,95
5/8 17 x 23 22,91
3/4 20 x 27 26,44
7/8 24 x 31 30,20
1" 26 x 34 33,24
1" 1/4 33 x 42 41,91
1" 1/2 40 x 49 47,80
1" 3/4 46 x 55 53,74
2" 50 x 60 59,61
2" 1/4 60 x 70 (old standard) 69,30
2" 1/2 66 x 76 75,18
2" 3/4 72 x 82 81,53
3" 80 x 90 87,88
3" 1/2 90 x 102 100,33
4" 102 x 114 113,03