This paper describes the newly developed P/M sprockets for silent chain system of DIG (DIRECT INJECTION GASOLINE) engines. The wear of silent chain and sprocket itself is severe. And DIG system sometime generates more carbon soothe than the other engines. So it is necessary to develop new P/M sprocket with high anti-wear characteristics. The combination of warm compacting and high temperature sintering is adopted in this development. Molybdenum-Nickel alloy steel powder is selected as the raw material.
