Size: Thread size of 3AN male coupler is 3/8-24 UNF, 4AN male coupler is 7/16-20 UNF. Size: Thread size of 4AN male coupler is 7/16-20 UNF, 6AN male coupler is 9/16-18 UNF. Size: Thread size of 6AN male coupler is 9/16-18 UNF, 8AN male coupler is 3/4-16 UNF.
