Which tool combination will make a perfect flare end for a good seal?

• A. Hammer and anvil
• B. Flare tool with a burnishing cone & 45 degrees flare angle
• C. Sharp wheel
• D. Pliers

Answer: (B)

Creating a perfect flare end comes from shaping the tube with a dedicated flaring tool that makes a precise, smooth edge and a consistent flare angle. The burnishing cone in that tool supports a controlled, gentle finishing of the tube edge as the flare is formed, which smooths any roughness and helps seal tightly. The 45-degree flare angle matches the mating parts so the flare sits flush and distributes pressure evenly, giving a reliable seal without gaps or stress concentrations.

Other approaches fall short because they don’t provide the controlled geometry or edge finish needed for a good seal. A hammer and anvil can deform or flatten the tube, ruining its round cross-section. A sharp wheel can create nicks or burrs that act as leak paths or crack starters. Pliers lack a proper shaping surface and won’t produce the correct flare geometry, often crushing or collapsing the tube instead of forming a proper flare.