Lower Brake Hard Line Thread Size?

I'm in the process of redoing a lot of stuff on my 74 Z1. I got some new/shorter brake lines due to my grips being a lot lower now.
The lower flex line I got from Z1 does not screw onto the hard line that goes into the caliper.
This is the line I got:
www.z1enterprises.com/brake-hose-10344-b...-chrome-swivels.html

What thread size is the stock hard line fitting? I want to see if I can find an adaptor. Or what else have you guys done to attach a new line?

I would try contacting Jeff Saunders at Z1Enterprises.com.

Possible adapter fitting. just guessing. Z1Enterprises --- Brake Adapter Female 10x1.25 to Male JIC-3 --- Part GRFM10125-03

Thanks. I actually did order that adapter and it wouldn't thread onto the hard line. I'm starting to think maybe the threads on the hard line are messed up. Even the stock hose was hard to thread on/off of it. Going to order a new hard line. That adapter should be right.
Thanks

your standard metric tubing nut for 4mm tubing is 10mm with a 1.0 pitch