Engineering Gadgets on Instagram: "For effective metal tube bending without damage, the best machine is a mandrel bender because it uses an internal support tool to prevent the tube from collapsing, wrinkling, or deforming. For large-radius bends where high precision is not required, a roll bender is another effective option."

ASTM D522 Mandrel Bend Test of Attached Organic Coatings Lab In US - Infinita Lab

Mandrel Testing | Cloud 9, A Wind River Company