John Guest shank fittings

Thinking about trying accuflex bev seal ultra 3/16" tubing but after the hassle of getting my other shanks I see the best and easiest way to connect bev seal is with John Guest fittings. They make a mfl threaded connector for disconnect and a shank fitting. My shanks are nipple shanks. I was going to try and grind off the barb on a couple of the throw away ones for practice. Also thought I could try to drill out the bore to 1/4". Anyone know if the John Guest fitting for the shank outlet is 3/16" or 1/4"? It fits 3/16" ID 5/16" OD line. Going to see if I could salvage the other shanks but not sure if going to 1/4" shank from 3/16" line mattered at all.

The shanks aren’t of a pipe threaded item… You can cut off the barbed fittings, then you have to know the thread size of the shanks and get a a piece that will adapt… I wouldn’t use bronze/brass fittings… Perhaps you take the shank down to your local hardware store to find out what size, the go to brew hardware… He’s got stuff nobody else has… Just saying… Sneezles61