A1-3

3/8 x 24 unf male fully threaded steel nut, SAE (double) flare, .562” long. Uses 3/8” wrench. This is the standard American brake line nut for use with 3/16” o.d. tubing with SAE (double) flare. 3/8” x 24 unf is standard American fine thread. 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!