An assortment of carbide tip concrete drill bits from The Hillman Group. Concrete drill bits are used in hammer drills to create pilot holes in concrete. Bits in this assortment feature a high-strength carbide tip to create more precise pilot holes. Variants included in this assortment come in diameters of 5/32" & 3/16" and range from 3-1/2" to 5-1/2" in length. Full assortments of #3546 contain six (6) refills comprised of Hillman item numbers #3547 - #3552.