https://www.youtube.com/watch?v=DilhwMrL91Q
https://yenkee-wiki.win/index.php/How_to_Choose,_Cut,_and_Bend_Sheet_Metal
As you cut, one side of the sheet steel will ride up and also over the lower jaw. Roll this item back and to the side, as you go to keep it from binding on the blade or getting in the way of your hand (Image 4).