3/8" x 24 unf male fully threaded steel nut, .562” long overall
SAE flare (45 degree/inverted/double)
Most common American nut
Uses 3/8” wrench.
This is the standard American brake line nut for use with 3/16”/4.75mm OD tubing with SAE flare.
Found on North American made cars and trucks for over 60 years.
Still widely used but metric is becoming common, if your vehicle has ABS you must be very careful to identify what nuts and flares you need.
Caution, this nut will thread very easily and loosely into a 10mm x 1.0 threaded port!