A power tool accessory for cutting tubular members includes a housing, an input shaft configured to be coupled to a rotary power tool, a transmission, and a cutting head removably received in a front end of the housing. The transmission includes an input gear and an output gear with a first plurality of teeth. The cutting head has a central opening, a cutting blade protruding into the central opening, and a second plurality of teeth engaged by the first plurality of teeth. A clamp assembly coupled to the housing is moveable between a first position where the cutting head is removable from the housing and a second position where the cutting head is retained in the housing. The cutting head receives a tubular member in the central opening with the cutting blade engaging the tubular member to cut the tubular member as the cutting head rotates about the tubular member.

A blade removably secured to a jaw for a power tool includes a base at a first end, a tip at a second end opposite the first end, a cutting edge extending between the tip and base, and an alignment projection extending from the base away from the cutting edge. The alignment projection facilitates proper positioning and secure attachment of the blade to the jaw.

A cutting device for cutting flat material, such as sheet metal, is disclosed. The cutting device includes a knife shaft to which at least one circular knife can be fastened and a positing device. The positioning device is configured to move the at least one circular knife in a released state along a longitudinal axis of the knife shaft and to fix it in a predetermined position on the knife shaft in a reversible and force-transmitting manner, wherein the positioning device has at least one effector configured to actuate a clamping means of the at least one circular knife. The cutting device is further characterized in that to actuate the clamping means, the effector is movable along an axis of movement that is skewed with respect to the longitudinal axis of the knife shaft.