If a flare splits when being made, it may be due to the age of the tubing. Old tubing becomes brittle after a certain period of use and cannot be flared satisfactorily. A remedy is to anneal the tubing by heating it to a dull cherry red or blue color and allowing it to cool in air or water. Pounding, rough handling, or bending the tubing tends to harden it. Hard-drawn tubing cannot be bent or flared unless annealed.
