Abstract: Selecting CPM10V steel as a model material, the present work reports a study on processing routes to improve relative density in the vicinities of graphite mold sidewall in vacuum hot-pressed highly alloyed tool steels. The experimental results show that an increase in hot-pressing pressure or temperature promotes near-full densification in regions adjacent to the graphite mold sidewall, i.e., the outer surface of the hot-pressed steel. When the hot-pressing pressure was increased from 30 MPa to 50 MPa at 1150 ℃, the relative density in the lower sidewall region increased from 98.49 ± 0.11 % to 99.18 ± 0.11 %, which is likely attributed to an increase in net pressure and thus an increase in the ratio of net pressure to powder flow strength. In addition, when the hot-pressing temperature was increased from 1150 ℃ to 1180 ℃ at 30 MPa, the relative density in the same region increased from 98.49 ± 0.11 % to 99.05 ± 0.06 %, due to a decrease in powder flow strength, also resulting in an increase in the ratio of net pressure to powder flow strength with the same net pressure. In both cases, the increased ratio of net pressure to powder flow strength enhances powder plastic flow and facilitates the elimination of pores between powders, leading to near-full densification. As a result of the improved densification near the outer surface, mechanical properties (specifically, hardness and bending strength) of the hot-pressed CPM10V are enhanced.