The DEWALT Rotary/Percussion Masonry Drill Bits have 130° Douglas Form carbide tips. They are ideal for drilling anchor, plastic, fixing or pipe work clearance holes. Suitable for drilling masonry, brick/block work and stone. . This DEWALT Masonry Drill Bit has the following specification: Diameter: 7mm. Overall Length: 150mm. Working Length: 82mm. DEWDT6557QZ