What is an important step to take when making a flare to prevent copper from splitting?

A key step in making a flare to prevent copper from splitting is to tighten and loosen the flaring tool. This process helps to relieve the stress on the copper tubing. When the flaring tool is initially tightened, the copper is compressed and formed into the desired flare shape. By loosening the tool slightly and then tightening it again, you ensure that the copper has a chance to relax and distribute the stress more evenly, reducing the risk of splitting or cracking during the flaring process.

Using a lubricant could help with the tool's operation, but it doesn't directly address the issue of preventing the copper from splitting. Leaving the flaring tool tight throughout the process may also increase the risk of splitting due to excess pressure. Heating the copper tubing could alter its properties, but it is generally unnecessary for making a flare and could lead to other complications. Thus, the correct approach focuses on manipulating the tension of the flaring tool to create a more secure and less stressed flare.