What should be done to the end of a tube that is to be flared?

• A. Leave burrs to reduce material loss
• B. Polish the cut end to remove any sharp edges that could cause cracking
• C. Apply thread sealant
• D. Clamp without finishing

Answer: (B)

When preparing a tube for flaring, you must remove burrs and sharp edges on the cut end. These flaws act as stress concentrators and can initiate cracks as the tube is formed into a flare or subjected to pressure. After cutting, use a proper deburring tool to smooth the edge inside and out so the end is square and free of burrs. A clean, smooth end lets the flare form correctly and seals properly, reducing the risk of cracks and leaks. Filling or sealing the end with sealants isn’t appropriate for flared connections, and leaving burrs or rough finishes can undermine the integrity of the flare.