Abstract: In order to economize chromium in high speed steels, a series of nonchromium and low chromium (1-2%cr) high speed steels have been studied. Silicon and manganese are used to replace chromium in steels. It has been found that when manganese content is raised more than 1%, the stability of austenite is so greatly increased that the steel can not be softened with usual annealing process, and the sensitivit to overheat is also increased. The non-chromium high speed steel with raised silicon. content (about 1.4% Si) has good mechanical and working properties, high resistance to oxidation; and its red hardness and cutting ability are not lower than that of 9 and 18 high speed steels. Cutting tools made by these new steels have been tested in production line in factories, results show that the non-chromium high speed steels have the same cutting life as that of 9 and 18 steels. The effects of chromium on the properties of high speed steels have been investigated. The red hardness of non-chromium high speed steel is not lower than that of 4%cr high speed steels, and sometimes even higher. Phase analysis indicates that the dissolved tungsten content in the solid solution of quenched non-chromium steel is higher than that of quenched 9 high speed steel, that explains why the non-chroniun high steel possesses, such excellent red hardness.