What is the recommended finish on the end of tubing before flaring to avoid cracks?

• A. Leave the cut end as is
• B. Polish the cut end to remove sharp edges
• C. Chamfer only
• D. Polish to smooth but not remove edges

Answer: (B)

Removing burrs and sharp edges from the cut end of tubing before flaring is essential. When you cut tubing, the outer edge and the inner surface can have burrs and a sharp rim. These imperfections act as stress concentrators and can crack under pressure or during the flare process. Polishing the cut end to remove those sharp edges gives a smooth, clean surface that allows the flare to form evenly and seat properly, while reducing the chance of crack initiation and damage to the flare seating area.

Leaving the cut end as-is leaves burrs that can propagate cracks. Chamfering alone may bevel the edge but won’t necessarily remove all burrs or sharpness, leaving potential stress points. Polishing to smooth out the surface ensures a smooth finish without leaving a sharp edge, which is the safest approach for reliable flares.