BRASS FLARE NUTS

Product Description

Brass Flare Nuts are specialized fasteners used to create high-pressure, leak-proof mechanical joints in tubing systemsmost commonly in HVAC, refrigeration, and automotive brake lines. Unlike standard nuts, they are designed to work in tandem with a flared tube end to create a metal-to-metal seal without the need for gaskets or PTFE tape.

1. How a Flare Joint Works

The connection relies on the geometry of the components:

• The Tube: The end of a copper or aluminum tube is expanded into a bell shape (usually at a 45 angle for plumbing/HVAC or 37 for AN/Aerospace).

• The Fitting: The flare nut is slid onto the tube before flaring.

• The Seal: As the nut is tightened onto a male flare fitting, it wedges the flared tubing between the nut and the fitting's nose, creating a high-pressure seal.

2. Forged vs. Machined Brass

In professional applications, the manufacturing process of the nut is critical:

• Forged Flare Nuts: These are stronger and more resistant to "stress corrosion cracking." They are preferred for refrigeration systems (like R-410A) where pressures are extremely high and temperature fluctuations are frequent.

• Machined (Hex) Flare Nuts: Often cut from hexagonal brass rod. While sufficient for low-pressure gas or water lines, they may have less structural integrity than forged versions under extreme vibration.