MANDREL FOR BENDING AND BENDING METHOD USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a mandrel for bending capable of reducing friction resistance between the mandrel and a work and effectively preventing generation of an inner face flaw and buckling of a work. SOLUTION: Narrow grooves 6 to hold a lubrication oil are formed on an outer peripheral face. By this method, the friction force between a cylindrical work W and a mandrel 5 in bending is reduced, the work W is surely prevented from causing of a sliding flaw and buckling with pushing force.