Secret metal lathe trick to make reduction fitting in 3 minutes

This is a cool metal lathe trick that I didn’t know before. As an example I made a copper reducer fitting to show the trick. Instead of a lathe tool I simply used a piece of stainless round steel. The trick is rolling the part instead of cutting. I was surprised how well it works. At the end of the video I show how to connect the hoses with a self-made tool without the use of hose clamps.