What is the process called when expanding the end of copper tube into a funnel shape to fit onto threaded male fittings?

• A. Beading
• B. Flaring
• C. Beveling
• D. Crimping

Answer: (B)

Flaring is the process of forming a tapered, funnel-shaped end on the copper tube so it can seal against a flare fitting. Using a flaring tool, the tube end is expanded into a conical shape (often about 45 degrees) that creates a seating surface for the flare nut and the mating fitting. When the nut is tightened, the metal surfaces press together to form a tight seal, which is why flaring is used for connections to threaded flare fittings.

Other techniques don’t create that necessary conical seal. Beading adds a small bump on the edge, beveling sharpens or bevels an edge for cutting or seating, and crimping compresses the end without producing a proper flare shape for a flare-type joint.