1. Raising the carbon content of steels produced by DHP to 0.8% increases their hardenability. The hardenability of hypereutectoid steels is less, which may be attributed to their marked structural hetero-geneity and the presence of a large amount of stable carbides. 2. In the annealed condition, the hardenability of P/M steels is less than that of conventional grades because steels produced by DHP are less prone to grain growth and are characterized by greater hetero-geneity and higher oxide contents. 3. Lowering the temperature of DHP reduces the extent of thermomechanical strengthening and consequently decreases hardenability. 4. Steels produced from iron powders containing manganese and silicon surpass in hardenability, in spite of their high oxide contents, manganese-free steels. 5. teels produced from coarser iron powders show greater heterogeneity and lower hardenability.