Brass Flare Nut – Short
The brass nut that clamps a copper tube’s flare onto an equipment’s threaded fitting.
AirGreen codeAG-RC-01001
514 316-2973 · sales@airgreen.ca
Quick facts
The brass flare nut (flare nut) connects a copper tube to a threaded fitting without brazing. The nut slides onto the tube, the tube end is flared with a flaring tool, then the nut threads onto the unit’s fitting and clamps the flare against it. Metal-to-metal contact makes the seal.
The connection for wall-mounted and multi-zone heat pumps
The indoor and outdoor units of wall-mounted heat pumps and multi-zone systems are generally connected with flares: no flame inside the home, and the unit can be disconnected if needed. A new nut replaces a nut that is lost, cracked or damaged, or lets you redo a flare from scratch during a line repair.
Seven diameters, from 3/16 in to 3/4 in
The nut is available for tubes of 3/16, 1/4, 5/16, 3/8, 1/2, 5/8 and 3/4 in outside diameter. Choose by tube size: a 1/4 in tube takes a 1/4 in nut. This is the short version, in a compact format.
A flare that does not leak
- Slide the nut onto the tube before flaring.
- Cut square, deburr while keeping the chips out of the tube, then flare with a tool matched to the fitting’s angle (45° on air conditioning equipment).
- Tighten to the torque specified by the unit’s manufacturer, with a torque wrench.
- Pressure-test with dry nitrogen before pulling a vacuum.
Connecting a refrigerant circuit is reserved for a qualified refrigeration technician.
Supplied and installed by AirGreen in Greater Montréal
Our refrigeration technicians flare and connect the lines of every heat pump in Montréal, Laval, Longueuil, on the South Shore and on the North Shore. RBQ licence 5645-9605-01. To check availability or get a quote, call us at 514 316-2973 or email sales@airgreen.ca with the diameter and quantity.
The braze-free connection on wall-mount heat pumps
The nut slides over the tube, the tube is flared, then the nut clamps the flare onto the unit’s fitting.
- Flare connections on wall-mount and multi-zone indoor and outdoor units
- Replacing a lost, cracked or damaged nut
- Redoing a fresh flare during a line repair
- Flare connections on refrigeration valves and accessories
7 sizes, one page
Each size has its own AirGreen code. Tap a row to select it.
| Diameter | AirGreen code |
|---|---|
| 3/16 in | AG-RC-01001 |
| 1/4 in | AG-RC-01002 |
| 5/16 in | AG-RC-01003 |
| 3/8 in | AG-RC-01004 |
| 1/2 in | AG-RC-01005 |
| 5/8 in | AG-RC-01006 |
| 3/4 in | AG-RC-01007 |
Outside diameter of the copper tube the nut slides onto, in inches.
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- Slide the nut onto the tube before flaring: it will not go on once the flare is made.
- Use a flaring tool that matches the fitting angle; air conditioning flare fittings are 45°.
- Tighten to the torque given by the equipment maker, with a torque wrench.
- Check for leaks with a dry nitrogen pressure test before pulling the vacuum.
You may also need
Pre-Insulated Line Set for Wall-Mounted Heat Pump – 50 ft Roll
A.C.R. Soft Copper Tube – 50 ft Coil
Leak Lock Thread Sealant – Blue and Gold
Dry Nitrogen – Cylinder
A.C.R. Copper Cap
A.C.R. 45° Copper Elbow (C × C)
A.C.R. Copper 90° Elbow – Short Radius (C × C)
A.C.R. Copper 90° Elbow – Short Radius, Male × Female (Street)Copper fittingsSee all
Frequently asked questions
How do I pick the right size?
By the tube’s outside diameter: a 3/8 in tube takes a 3/8 in nut. It is also the size of the matching fitting on the equipment.
Should I put oil or sealant on the flare?
Follow the equipment maker’s instructions. Many makers call for a clean flare, sometimes with a drop of refrigeration oil, and a torqued connection.
Can an old nut be reused?
If it is not cracked, distorted or damaged at the thread. When in doubt, a new nut avoids a leak.
Can you make the connections?
Yes. Our technicians flare, connect and leak-check on every heat pump installation in Greater Montréal.
Flare nuts for leak-tight connections
Tell us the size and the quantity: we confirm availability and send you a quote. Or let our technicians install it for you.
Specifications from the manufacturer’s documentation, checked on October 7, 2026.