Mech oil pressure gauge connection size...?

I need another braided steel line for an oil pressure gauge. I've got one in a car already, but I can't remember what size it was. The threaded connector on the oil pressure gauges seems to be a generic standardized size. Anyone know off hand what it is? AN-something?

Can't translate to an but most oil gages use 1/8"tubing.

My Autometer uses a -4 line, & a -4Male to 1/8"NPT Male adapter @ the block. The Gauge came w/ an adapter for the gauge side.

Anyone know the size of the threaded connector on the back of the gauge? A couple different brands of oil psi gauges I've had have all had the same connection size. Has to be a generic universal thing?

Most of 'em I've seen are common, ordinary, "American" 1/8 pipe thread, just like the engine block.

That's what I was thinking. Next time I go to the hardware store I'll just have to bring along the gauge and see if I can find a nut that fits, just to confirm the size.