Honeycomb structure forming tool (100, 300) comprising: a first mold (10) disposed on an upstream side in an
extrusion direction (X) of a kneaded material of a molding
raw material, and in which a central portion (15) on the side of a kneaded material
discharge surface (18) has a convex portion (16) projecting toward a downstream side in the
extrusion direction (X); and an annular second mold (20) arranged on the downstream side of the first mold (10) and having a shape complementary to the convex region (16), wherein first kneading material introduction holes (12) and first grid slots (11) communicating with the first kneading material introduction holes (12) are formed in the
central region (15) of the first mold (10), in a
peripheral region (17) surrounding the
central region (15) of the first mold (10), the first kneading material introduction holes (12) are formed such that they extend through the
peripheral region (17) of the first mold (10), second kneading material introduction holes (22) are formed in the annular second mold (20), into which the kneading material discharged from the first kneading material introduction holes (12) formed in the
peripheral region (17) of the first mold (10) is introduced, and second grid slots (21) communicating with the second kneading material introduction holes (22), Positions of the opening of the first kneading material introduction holes (12) of the peripheral region (17) of the first mold (10) do not coincide with the positions of the openings of the second kneading material introduction holes (22) of the second mold (20) at least in a part of the
honeycomb structure molding tool (100, 300), an
abutment surface (14) of the first mold (10) is an end face of the peripheral region (17) of the first mold (10) on a downstream side with respect to the
extrusion direction (X), and an
abutment surface (24) of the second mold (20) is an end face of the second mold (20) on an upstream side with respect to the extrusion direction (X), and wherein the
honeycomb structure forming tool (100, 300) comprises: a gap region (35) between an outer peripheral surface of the convex portion (16) of the first mold (10) and an inner peripheral surface of the annular second mold (20) for extruding the kneaded material into a ring shape, and a groove region (31) having a plurality of grooves formed in the abutting surface (14) of the first mold (10) and / or in the abutting surface (24) of the second mold (20), and in which the movement of the kneading material between the first kneading material introduction holes (12) and the second kneading material introduction holes (22) is carried out, wherein the abutting surfaces (14, 24) of the first mold (10) and the second mold (20) are in contact with each other except for a region in which the groove region (31) is formed.