Impregnated diamond drill bits continue to be effective in the hardest and most abrasive formations, including dolomites and cherts that cannot be sheared effectively by PDC.
(Galleta, Waspshaw, and Wrighton 1993).

An impregnated diamond bit comprises of a tungsten carbide matrix integrated with a natural and synthetic diamond cutting elements. The multi-layered diamond structure is cast into an abradable matrix designed to wear away at a predetermined ratio creating a self-sharpening cutting structure. Hence, as the matrix wears in a controlled manner, new diamonds are continuously exposed. The cutting mechanism is very similar to that of a grinding wheel. The small diamond size and the large quantity of diamonds with limited exposure make these bits very durable and wear resistant.

Impregnated diamond bits are more efficient drilling in the very hard and abrasive formations that continue to limit PDC and roller cone bit life. The multi-layered, small diamond size make them more durable and very often faster than traditional natural diamond bits and TSP bits.

To increase durability requires an increase in the cutting elements and therefore the support structure (blades or pads). This results in a reduction in hydraulic area. The first generation impregnated diamond bits were designed to be durable. Generally, these bits had a dense cutting structure with a limited hydraulic area. A new generation of DuraDiamond bit features a very open Hydraulic layout as compared to traditional impregnated Diamond bits.