AC Nut 1/4 x 3/8 Inch Heavy – Heavy Duty Brass Reducing Flare Nut for Split AC Copper Pipe | Universal Refrigerant Line Union Nut

Heavy-duty 1/4" x 3/8" brass reducing flare nut used where a split AC's copper refrigerant line steps between two pipe sizes — joining a 1/4" flare connection to 3/8" pipe (or vice versa) in a single fitting. The thicker "heavy" build resists cross-threading better than a standard nut across repeated installation and servicing. Compatible with all AC brands; confirm both pipe ends before ordering.