Method of producing honeycomb structure molding die

A method of producing a honeycomb structure molding die for the use of molding a honeycomb structure body, the die having a plurality of feed holes through which molding material is fed and a plurality of slit grooves formed in approximating a lattice arrangement communicated with the corresponding feed holes, the method comprising steps of:

• preparing a metal material of a plate shape having a feed hole formation surface in which the feed holes are formed and a slit groove formation surface in which the slit grooved are formed;
• forming the feed holes with a depth in the feed hole formation surface toward the slit groove formation surface of the metal material without penetrating the metal material;
• forming the slit grooves of a straight-line shape or a line shape approximating a straight line in the slit groove formation surface of the metal material in approximating a lattice arrangement while moving a thin circular grindstone blade which is rotating in a straight-line direction or a line direction approximating a straight line and in reciprocating motion in order to cut the metal material with a depth of reaching the fed holes;
• and
• removing fine metal powder, generated by cutting the metal material, attached to the thin circular grindstone blade every forming the slit groove in the metal material.