US Standard Sizes
The standard specifications of pipe fittings that are globally accepted are Metric and Standard English.
Standard English sizes are calibrated in inches and their size ranges from 1/8" to 36".
Common sizes are:
1/8"
1/4"
3/8"
1/2"
3/4"
1"
1 1/4"
1 1/2"
Reference[]
Link[]
