Contractors use Ajax carbide drill steel products to drill holes in concrete, rock and other dense materials. For Mining and Quarries, Drill steels are used to drill holes in granite, marble, rock and other dense materials. Ajax manufactures Carbide Speed Bits in 5/8" to 1-5/8" Diameters up to 44" of Drill Depth, and in Shank Sizes of 7/8" x 3-1/4", 7/8" x 4-1/4", and 1" x 4-1/4".