Rotary Hammer
Affiliate link — we may earn a commissionA rotary hammer uses a piston-driven mechanism to deliver heavy blows along the bit axis while simultaneously rotating. It hits much harder than a hammer drill, which uses cam plates for lighter, faster taps. Rotary hammers handle holes from 3/16-inch to 1-1/2-inch in concrete, brick, and stone. Most use SDS-Plus bits for holes up to about 1-1/8-inch and SDS-Max for larger work. Many have three modes: hammer-and-rotation for drilling, hammer-only for light chiseling, and rotation-only for driving anchors. Cordless 18V rotary hammers have replaced corded models for most residential and light commercial work.
Why It Matters
If you drill more than a few holes per year in concrete, a rotary hammer finishes the job in a fraction of the time a hammer drill takes. A 1/2-inch hole in 4-inch concrete takes a rotary hammer about 10 seconds. The same hole with a hammer drill takes 30 to 60 seconds of hard pushing. For anchoring, tapcons, and concrete fasteners, it's the right tool.