Which tool and features will make a perfect flare for a good seal?

• A. Hammer and chisel
• B. Flare tool with a burnishing cone & 45 degrees flare angle
• C. Simple file
• D. Tape and wrap

Answer: (B)

Forming a reliable seal hinges on a clean, precisely shaped flare with the correct geometry. A flare tool that includes a burnishing cone and a 45-degree flare angle delivers that by creating a smooth, uniform flare edge and finishing the flare surface so it seats tightly against the mating nut. The burnishing cone smooths and slightly compresses the edge, removing burrs and preventing cracks or sharp corners that could leak under pressure. The 45-degree angle is the standard geometry for this type of flare, providing the right contact surface between the flare and the nut to form a tight seal when tightened to specification.

Hammering with a chisel can distort or crack the tubing and ruin the flare geometry. A simple file can’t consistently create the precise flare angle or finish required for a good seal. Tape and wrap don’t form a genuine flare and won’t provide a leak-tight connection in a fitting system.