... 2. Three function 3. BMC packing 4. Strong power motor 5. Metal gear housing for heavy duty work Rotary hammers are similar in ... . Therefore, they require special bits which can lock into the rotary hammer and continue on spinning while smashing away.A number of ... in use today are: SDS, SDS-MAX, and SPLINE SHANK.Rotary hammer drills have an oil filled gearbox, which allows them to ...