IN JAPANESE STANDARD (JIS G 3112-1987)
Nominal Size  Nominal Diameter (D) mm  Nominal Perimeter (L) cm  Nominal Sectional Area (S) mm2  Mass Per Meter Run kg/m  Max Space Between Ribs mm  Height Of Ribs  Angle Between Rib And Axis
           Min mm  Maxmm  
16  15.9  5.0  1.986  1.56  11.1  0.7  1.4  
19  19.1  6.0  2.865  2.25  13.4  1.0  2.0  
22  22.2  7.0  3.871  3.04  15.5  1.1  2.2  
25  25.4  8.0  5.067  3.98  17.8  1.3  2.6  

IN BRITISH STANDARD (BS4449-1988)
Nominal Size mm  Cross Sectional Area mm2  Mass Per Meter Run kg/m
16  201.1  1.579
20  314.2  2.466
25  490.9  3.854