The combination of diamonds and matrix determine the performance of an impregnated bit. The simultaneous erosion of the matrix and the diamonds make the bit self sharpening. The ideal combination of optimal peneration rate and wear resistance matched to achieve the ultimate in drilling economy. In most geological formations, impregnated bits are more economical to use than surface set bits and they provide additional benefits. Conventional bits are primarily used in shallow holes as the rod needs to be retieved with each core sample. Thin kerf bits provide a larger core size for the same diameter hole.