Abstract: A pneumatic hammer is an impact tool to be used in the construction industry and in mechanical engineering for chipping metal, scaling welds and chipping castings. The pneumatic hammer comprises a housing accommodating a barrel axially movable relative thereto, and a hood which is axially biased by a spring. The barrel is adapted to receive a tool having a non-circular cross-section. The hood has a non-circular hole for passage of the tool. Intermediate members are disposed between the hood and the tool and are in contact with the tool and comprise bodies of revolution rotatably mounted in the hood. The intermediate members define the non-circular hole of the hood, the shape of the hole corresponding to the cross-sectional shape of the tool. With such construction, the sliding friction between the tool and the side wall of the hood is replaced by the rolling friction between the tool and the intermediate members thereby reducing vibrations and lowering heating of the tool.