... Drilling Description about sell rock bits,tricone bits, diamond bits,PDC bits,TCI bits, steel tooth bits, milled tooth bits, rock ... 5-1/8” to 13-1/2”.There are different PDC (polycrystalline diamond compact) grades and shapes applied for rock formations ... ,127,437,517,617,637 TypeTricone bits, Steel tooth bits, PDC bits Applicable water well, oil field, construction, geothermal, directional boring ...