Abstract: A method of refining molten metal includes the steps of reduced-pressure-refining molten metal in a heated vessel, adding slag-forming agents into the refined molten metal while keeping the molten metal in the vessel, or after pouring the molten metal into another vessel, re-refining the molten metal by heating the molten metal with inert-gas plasma and while stirring the molten metal as occasion demands. Preferably, the refining apparatus includes two adjacent chambers, each chamber isolated from the surrounding atmosphere. The chambers can be connected with, or separated from, each other and each chamber is provided with an exhaust device. One of the chambers is provided with an induction heating refining furnace, and the other chamber is provided with inert gas plasma heater. The apparatus also includes a re-refining vessel which is transferable between the two chambers, and a material feeder for feeding slag-forming agents into the re-refining vessel.

Abstract: A rotary-type sheet cutter for cutting a continuous sheet material comprising a stationary blade having an end edge extending along the widthwise direction of the sheet material; and a rotary blade having an end edge which rotates about a rotary axis extending along the widthwise direction of the sheet material during rotation of the rotary blade, the end edge of the rotary blade intersection-contacting with that of the stationary blade under pressure so as to cut the sheet material along the widthwise direction when the rotary blade rotates. The rotary blade is formed by bending a flat plate along a bend line which is brought into a state of extending along the widthwise direction of the sheet material, and the end edge and the bend line are arranged to form an angle opening toward a cutting starting side.

Abstract: A section steel wire for an oil ring for use in an internal combustion engine, consisting essentially of, by weight, 0.6 to 1.5% carbon, not more than 1.5% Si, not more than 1.5% Mn, more than 20% and not more than 25% Cr, and optionally containing at least one group selected from three groups consisting of a group of at least one element of Mo and W in total amount of not more than 3% of "Mo+W/2", another group of at least one element of V and Nb in total amount of not more than 3% of "V+Nb/2" and still another group of at least one element selected from not more than 12% Co, not more than 5% Ni and not more than 5% Cu, and balance of Fe and unavoidable impurities. The section steel wire has a Vickers hardness of HV 300 to HV 450 and has a substantially H-or X-shaped cross-section. A thickness ratio of the thickness of the web portion bridging the flange portions to the total thickness (T) of the flange portions is not greater than 0.3.

Abstract: A two-piece oil ring, for use in an internal combustion engine, with the oil ring being made from a martensitic stainless steel material having high consisting essentially of more than 0.8 wt % but less than 0.95 wt % of C, not more than 1.0 wt % of Si, not more than 1.0 wt % of Mn, from 15.0 wt % to 20.0 wt % of Cr and a balance substantially Fe and incidental impurities. The oil ring has a hardness ranging from HV300 to HV450 and a substantially H- or X-shaped cross-section. A web portion interconnecting left and right halves of the H- or X-shaped cross-section has a thickness not greater than 0.3 in terms of the ratio of the total thickness of the ring. Oil passage holes are formed in the web portion. A nitrided layer is formed on the sliding surface thereof which makes a sliding contact with the inner surface of a cylinder of the engine. The material may further contain suitable amounts of at least one of Mo, W, V, Nb, Ni and Co.