You are drilling through a concrete foundation wall or into concrete block and your standard drill bit walks across the surface at the start, making a wandering hole that will not accept the anchor. Or the bit shanks under impact and the hole ends up oversize. 6-inch SDS-plus carbide-tipped hammer drill bit, 1/4-inch diameter. SDS-plus shank fits standard SDS-plus rotary hammer chucks — the go-to tool for concrete drilling on the job site. Carbide tip cuts fast through cured concrete without walking. The 1/4-inch diameter is the right size for 1/4-inch Tapcon anchors or similar concrete screw applications. 6-inch length gets you through typical concrete wall thicknesses in one pass without the bit quitting short of the substrate. Standard on foundation contractors, concrete crews, and mech Stocked at Crofton Lumber and Akron Lumber.