A manufacturing process of a monobloc vaned disc including a cutout by abrasive water jet of a block of material in general form of a disc, carried out so as to remove material from the block at a level of inter-vane spaces to reveal vane preforms extending radially from a hub, the cutout by abrasive water jet including, for making each inter-vane space: a first triple-axis cutout of a piece passing through the thickness of the block, used such that the cutout piece escapes from the block automatically by gravity; followed by at least one enhancement cutout.