As for end face form computation manner, and end face form computation device null ideal form

摘要

PROBLEM TO BE SOLVED: To provide a method for calculating the end shape of a columnar metallic material and a device thereof which are capable of automatically calculating the ideal end shape of the columnar metallic material which differs per production lot. SOLUTION: On steel product laid in parallel to the z-axis of a rectangular coordinates system, an end shape calculation device calculates an ideal end shape which is free from burrs according to the following procedure. First, on the end and cylindrical surfaces of the steel product, the surface shape of a range where no burrs are deemed to be present, is measured (S110, S120). Next, an equation which is most reliable to represent the end face of the steel product is obtained by the method of least squares (S130). Then, the coordinate of the point of intersection where this equation and the equation of a straight line in parallel to the z-axis on the cylindrical surface of the steel product intersects, is calculated, and this coordinate is regarded as a coordinate which is located on the ridge of the ideal outer periphery of the end face (S140-S170).