Beer line Hex Nut size?

I’m in the process of building a Randall for my kegerator out of a stainless steal filter canister I have.  The issue I’m having is that I can’t find what the size of the standard hex nut is that gets screwed into the keg coupler.  I need to find the male equivalent to attach to the actual randall.  I’ve looked on several websites, but none of the hex nut descriptions actually give the specs of the nut.  Can anyone help?  (the nut I’m talking about http://www.kegworks.com/connectors-for-beer-lines-394-p16540)

Thanks,
Matt

http://www.kegworks.com/hex-nut-for-beer-lines-1170-p20552

It’s right there under specs. 7/8" x 14 straight pipe thread.

Thanks!

It’s called a 1/4 inch 45 degree flare fitting.  I’m guessing you’d need a male 1/4 inch flare to male NPT fitting.