About Flare Fittings

Flare fittings we offer are SAE 45° standard brass fittings, intended for use with soft (annealed) copper tubing (L & K types) for distribution of natural & LPG/propane gas (gas tank or supply line to boiler/furnace/water heater heater), heating oil (oil tank to boiler/burner), water, refrigerant, air, oil and many other gases and liquids used in plumbing, heating, HVAC, automotive and industrial applications.
Flare fittings are inherently vibration-resistant and are ideally suited for applications where the tube has to be securely connected to a piece of equipment which vibrates a lot.

Frequently Asked Questions

Q: Which size flare fittings to use with copper tubing?
A: All flare connection sizes correspond to the outside diameter of copper tubing with which they are used. For example, 3/8" flare fitting (or flare nut) is used with 3/8" OD copper tubing. Note that we do not specify the CTS of the copper pipe, since all types of copper tubing can be specified by the OD, but not all (such as refrigeration/ACR) can be specified in CTS.

Q: Are flare nuts included with the fittings?
A: No, flare nuts are sold separately from the fittings and should be of the same size as flare fitting - for example, 1/2" male flare fitting would need a 1/2" flare nut.

Q: What is the difference between standard and forged brass flare nuts?
A: Forged brass nuts are mostly intended for high-vibration & high pressure applications (hydraulic, refrigeration, motors, etc.). Short nuts are common for heating oil, propane gas lines, etc.

Q: What kind of copper pipe/tubing can be used with flare fittings?
A: All types of soft (annealed) copper tubing - K, L, ACR/refrigeration (except M type).
Note that standard copper pipe should not be used with flare fittings since it would split during flaring, creating a leak pathway.

Q: What kind of tools are needed to make a flare connection?
A: A copper flaring tool with proper size flaring cones to make a flare and (2) wrenches or pliers to tighten the connection.