HQ HQ3 Diamond Core Drill Bit for Drilling Soft Fractured Abrasive Clay , Sandstone Exploration Drilling Products: The impregnated diamond bits are the most commonly useful bits in the mineral exploration industry, as they have the widest range of application. The carefully selected grades of high quality synthetic diamond are distributed in the depth of impregnated bit's matrix series. The matrix layer of the crown contains a uniform distribution of these crystals that are