Abstract: A press apparatus 1 includes: a first die part 2 having a first working surface 2a; a second die part 3 having a second working surface 3a; a first support member 4 that supports the first die part 2; and a second support member 5 that supports the second die part 3. At least one of the first and second die parts 2 and 3 provides a clearance S1, S2 present in at least a portion of an overlap region R1, the overlap region being overlapped by the first and second working surfaces 2a and 3a as viewed in the press direction, the dimension of the clearance in the press direction in a no-load condition being non-uniform along two orthogonal directions as viewed in the press direction. The minimum dimension of the clearance Si within an inner region R1u in the no-load condition is smaller than the minimum dimension of the clearance S1 within an outer region R1s in the no-load condition, the inner region defined by, and located inward of, the middle line between the centroid G and edge of the overlap region R1.

Abstract: There is provided a hot forged product having excellent wear resistance and fatigue strength even when the hot forged product is produced with a thermal refining treatment and a case hardening thermal treatment after hot forging omitted, and having a chemical composition consisting of, in mass %, C: 0.45 to 0.70%, Si: 0.01 to 0.70%, Mn: 1.0 to 1.7%, S: 0.01 to 0.1%, Cr: 0.05 to 0.25%, Al: 0.003 to 0.050%, N: 0.003 to 0.02% with the balance being Fe and impurities. The matrix at the depth of 500 ?m to 5 mm from an unmachined surface of the forged product is a ferrite-pearlite structure, in which a pro-eutectoid ferrite area fraction is 3% or less or a pearlite structure, and the average diameter of pearlite colonies in the pearlite structure at the depth of 500 ?m to 5 mm from the unmachined surface is 5.0 ?m or less.

Abstract: There is provided a hot forged product having excellent wear resistance and fatigue strength even when the hot forged product is produced with a thermal refining treatment and a case hardening thermal treatment after hot forging omitted, and having a chemical composition consisting of, in mass %, C: 0.45 to 0.70%, Si: 0.01 to 0.70%, Mn: 1.0 to 1.7%, S: 0.01 to 0.1%, Cr: 0.05 to 0.25%, Al: 0.003 to 0.050%, N: 0.003 to 0.02% with the balance being Fe and impurities. The matrix at the depth of 500 ?m to 5 mm from an unmachined surface of the forged product is a ferrite-pearlite structure, in which a pro-eutectoid ferrite area fraction is 3% or less or a pearlite structure, and the average diameter of pearlite colonies in the pearlite structure at the depth of 500 ?m to 5 mm from the unmachined surface is 5.0 ?m or less.

Abstract: In the pulling of a single crystal, hitherto, it is difficult to reduce the OSF density while the deformation rate is held down within the tolerance, so that it is difficult to improve the quality and productivity. In the present invention, a deviation from a true circle in each part of a single crystal S.sub.n-1 which was pulled in the preceding batch is found and the pulling speed pattern f.sub.pn-1 (L.sub.1) in the preceding batch is updated (f.sub.pn (L.sub.1)) before a single crystal S.sub.n is pulled, in order to pull the single crystal as fast as possible so that the OSF density is small while the deviation is within the tolerance.