The disclosed drill tools have metal matrix composite (MMC) or steel alloy bodies that are formed around one or more pre-fabricated components using either a casting or infiltration process. The pre-fabricated components are made of sintered, infiltrated, and/or cemented particles of an ultrahard material, and may form any suitable portion of the bit blades. The pre-fabricated components may be loaded into a machined mold, and the mold cavity is subsequently filled with powder, such as tungsten carbide powder, filler metal powder, binder metal powder, or combinations thereof. During a casting or infiltration process, the mold and pre-fabricated components are heated to a sufficient temperature to melt the binder metal and/or filler metal, wherein the molten metal superficially interacts with the inner surfaces of the pre-fabricated components to form a metallurgical bond to secure the pre-fabricated components to the bit body.