Once you have the thread size, it is important to verify the pitch The easiest way is to follow the following steps Count the number of thread crest over a ¼" Multiply that number by 4 to get theExternal Pipe Threads per ISO 2281, Pipe threads where pressuretight joints are not made by the threads These pipe threads are also known as Whitworth pipe threads Where D = MajorThread G1/8″ G1/4″ G3/8″ G1/2″ G5/8″ G3/4″ G7/8″ Thread diameter mm 9728 955 301 Core diameter mm 8566 587
G1 16 G1 8 G1 4 G3 8 G1 2 G3 4thread Ring Gauge G Pipe Thread Ring Gauge Precision External Screw Gage Pitch Thread Test Tool Aliexpress