The hammer drill I used in the tests was the 18-volt Makita BHP452, and the rotary hammer was a 1-inch Bosch Bulldog 11255VSR. To test battery life, I put a piece of 3⁄4-inch plywood on a few ...

Watch as the Bosch GBH 180-Li cordless rotary hammer drill undergoes a complete disassembly and restoration. This tool, damaged by rough use, had a worn switch but an intact control board.

Trevor Raab Both rotary hammer drills, and hammer drills have switches for drill and hammer modes. The Bosch rotary hammer drill (left) has modes for drill + hammer, drill only, and hammer only.

RH228VC Bulldog Extreme Max rotary hammer drills holes up to 1 1/8-inches in diameter. Enhancements include a longer piston and impact bolt, combined with a precision-machined striker, which Bosch ...