Abstract: A seat reclining mechanism is provided in which engagement of a first engaging portion and a second engaging portion is performed in the vicinity of the center of a pawl in its width direction, without providing a member protruding in the thickness direction of the pawl and without reducing the strength of the pawl. The first engaging portion is an engaging groove which opens toward a side surface of the pawl and extends in a direction intersecting the sliding direction of the pawl at one flat surface side in the thickness direction of the pawl.

Abstract: Ceramics adapted to be enveloped in a casting having a cumulative particle size distribution such that the percentage of particles with sizes of less than 44.mu. lies within the range of 14.5-50% and the balance consists of particles the maximum size of which ranges from 500-2,000.mu., in order to produce vibration-resistant ceramic parts which may be enveloped in a casting.

Abstract: Ceramic fiber molding for manifold reactors in which Al.sub.2 O.sub.3 --SiO.sub.2 ceramic fibers or SiO.sub.2 ceramic fibers are employed to form a molded product having a hardness of 20.degree. - 55.degree., a tensile strength of 120 - 1500 g/cm.sup.2 and a molded density of 0.06 - 0.35 g/cm.sup.3.

Abstract: A sintered alloy having improved wear resistance at high temperatures, comprising a soft, predominantly iron matrix having a Vickers hardness of 100-200 containing more than 5 but at most 20% Mo, together with 0.5-1.5% carbon and at least one additive selected from the group consisting of nickel, cobalt and chromium, with said additive constituting at most 25% by weight of said alloy, and most of said molybdenum being contained in Mo-Fe particles having a Vickers hardness of 600-1300 which are uniformly distributed within said matrix and have an average diameter of 20-70 microns.

Abstract: An upset-forged poppet valve wherein at least the head portion and a part of the neck is made of a high temperature super alloy while the remaining portion is made of a conventional valve steel, said two materials being connected by friction welding before said valve is forged. The method comprises two steps of first friction-welding two rods of said two materials and then forming the connected single rod into the poppet valve by upset-forging.

Abstract: Iron-base sintered alloy for the valve seats of internal combustion engines is an iron-base alloy powder containing, by weight, 6 - 20% chromium less than 2.0% nickel, and carbon 0.2 - 1.5%, together with at least one additive selected from among 0.3 - 1.5% manganese, 0.2 - 1.5% sulfur, 0.5 - 8% molybdenum, and 0.5 - 2.5% silicon, and molded to a sintered density of 6.2 - 6.8 g/cm.sup.3.

Abstract: Apparatus for manufacturing spherical hollow particles which provides a large number of individual linear water jets arranged in a ring and converging at a single point, so that a molten metal may be passed through this ring of water jets and converging point.

Abstract: The present invention relates to an anti-wear ferrous sintered alloy composed of carbon, molybdenum, phosphorus, boron, and, if desired, copper, and the balance iron.

Abstract: A method for manufacturing spherical hollow particles by providing a large number of individual linear water jets arranged in a ring and converging at a single point, and passing a molten metal through this ring of water jets and converging point.