A method of characterising a metallic material that comprises the steps of: a. providing a plate of metallic material simply supported between two parallel rollers, said rollers having the same diameter; b. bending the plate by providing an external force, F, via a bending knife, said force acting in a plane perpendicular to the plane formed by the centres of the rollers and which intersects the plate at the centre line between the rollers, said bending knife extending at least the entire length of the plate; c. the method characterised by comprising the step of calculating a cross-section moment, M, of the metallic material using the following equation: M = F ⋅ L m β 1 2 ⋅ co s 2 β 1 where F is the applied bending force, L m ( β 1) is the moment arm at angle β 1, calculated according to the following equation: L m β 1 = L 0 − R k + R d ⋅ sin β 1 where L 0 is half the die width, R d is the radius of the die edge, R k is the radius of the knife, and β 1 is the bending angle, wherein the bending angle, β 1, is the angle moved by the surface normal of the plate at the contact point with one of the rollers during bending by the external force, calculated as 90° minus the acute angle between the normal vectors of the start and bent planes of the plate, the start plane corresponding to the plane formed by the centre lines of the two parallel rollers, and the bent plane corresponding to the plane formed by the centre line of one roller and the line of contact between that roller and the plate, which plane contains the normal of the plate at the point which contacts the roller. a. providing a plate of metallic material simply supported between two parallel rollers, said rollers having the same diameter; b. bending the plate by providing an external force, F, via a bending knife, said force acting in a plane perpendicular to the plane formed by the centres of the rollers and which intersects the plate at the centre line between the rollers, said bending knife extending at least the entire length of the plate; c. the method characterised by comprising the step of calculating a cross-section moment, M, of the metallic material using the following equation: M = F ⋅ L m β 1 2 ⋅ co s 2 β 1 where F is the applied bending force, L m ( β 1) is the moment arm at angle β 1, calculated according to the following equation: L m β 1 = L 0 − R k + R d ⋅ sin β 1 where L 0 is half the die width, R d is the radius of the die edge, R k is the radius of the knife, and β 1 is the bending angle, wherein the bending angle, β 1, is the angle moved by the surface normal of the plate at the contact point with one of the rollers during bending by the external force, calculated as 90° minus the acute angle between the normal vectors of the start and bent planes of the plate, the start plane corresponding to the plane formed by the centre lines of the two parallel rollers, and the bent plane corresponding to the plane formed by the centre line of one roller and the line of contact between that roller and the plate, which plane contains the normal of the plate at the point which contacts the roller. F is the applied bending force, L m ( β 1) is the moment arm at angle β 1, calculated according to the following equation: L m β 1 = L 0 − R k + R d ⋅ sin β 1 L 0 is half the die width, R d is the radius of the die edge, R k is the radius of the knife, and β 1 is the bending angle,