Nippon Piston Ring was established during the period of 1931-1934 in the wake of Japan’s total industrialization and, as the name suggests, manufactured only piston rings at that time. However, nowadays the proportion of rings of all engine parts produced by the plant of NPR, is 46%. The remaining 54% comprises of sleeves, piston pins, camshafts, rock arms, transmission synchronizers, guiding valve seats. The largest shareholders of NPR are Nissan and Toyota. In Japan, NPR has six plants and one in the United States (co-ownership with the former AE Goetze NA, and now with the Federal-Mogul). NPR does not have factories in third world countries, except two joint ventures for the production of parts for the local markets in Taiwan and Indonesia.
NPR NPR delivers parts to manufacturers of all Japanese engine manufacturers such as Nissan, Toyota, Mazda, and Daihatsu. Fuji Heavy Industries buy rings, camshafts and sleeves from NPR. And in Europe, Mercedes-Benz and Mahle are NPR’s biggest ring customer. Mr. Schoettle organized Schoettle Motorenteile firm in 1973 - exclusively for NPR ring trade in Europe. The business slowly expanded, and thus NPR bought out Schoettle shares of SM and made the firm’s sales office in Europe, Africa and parts of Asia. Since SM was a well-known trademark in the industry, the name remained the same.
Now, 25 years later, SM employs 20 people in Gauloher. The SM marking is punched in all rings, which are made only for sales through Schoettle. And on the others, which are used on the island - for example, for Japanese engines – there is a mark N. During the manufacturing process laminating steel bars are spiraled onto the mandrel and then cutting and exposing harding and chromium-plating. Thus there is excluded defect of metallurgical character – when casting in iron it can form a cavity but when rolling iron - nothing. NPR produces steel oil scraper rings from the 50’s, and compression - from the 70's.