Brass fix

I need to make a taper of brass with a female thread that’s 3/8 at 12tpi, which is a very coarse thread. It turns out a place called Tracy Tools in Devon carries these taps, so I’m not going to have to make one. However, it’s not a usual size, so I had to check with the person paying that I could get this one tool for this one job. I /could/ make one – but I really don’t want to.