Heavy Duty (HD) Straight shank carbide drills bits are designed for use in a hammer drill equipped with a 3 jaw Jacobs type chuck. The bits are Specifically engineered for high durability and meet ANSI standards and can be used to drill in concrete, block, brick and soft stone.Heavy Duty straight shank carbide drill bits are designed for use in hammer drills. The drill bits are manufactured from high grade alloy tool steel with a carbide tip to provide long life in most concrete and masonry materials. The specially designed flute provides rapid removal of dust which prevents excessive wear resulting in longer bit life. Each drill bit is precision ground to ensure straightness for faster drilling.