When mechanically cleaning a tube, how far should the end of the tube be abraded?

When mechanically cleaning a tube in preparation for a fitting, the end of the tube should be abraded so that it is only slightly more than the depth of the fitting socket. This approach ensures that a clean surface is provided for a proper joint, allowing for an optimal seal when the tube is inserted into the fitting.

Abrading just beyond the socket depth is crucial because it removes oxidation, contaminants, and any irregularities that may prevent a tight fit. If the tube is abraded too much, it may cause a gap between the tube and fitting, leading to insufficient engagement and a potentially weak joint. Therefore, the goal is to achieve enough surface area for a secure connection without compromising the fitting's integrity. Also, ensuring that the abrading depth is slightly more than the socket depth gives enough allowance for any minor variations in fitting depth while still achieving a strong and reliable connection.