Work machine

A work machine comprising:

• a case part with hollow shape comprising a cylinder, the cylinder being in a tubular shape extending in a first direction and comprising an inner wall;
• and
• a piston part capable of moving in the first direction inside the cylinder, the piston part cooperating with the case part to define a pressure chamber inside the case part, and striking a fastener by moving to one side in the first direction due to a pressure of a gas inside the pressure chamber, wherein
• the piston part comprises:
• a base member comprising a sidewall facing the inner wall of the cylinder;
• a first seal member attached to the base member to be interposed between the sidewall and the inner wall;
• and
• a second seal member attached to the base member to be interposed between the sidewall and the inner wall, and arranged at a position different from the first seal member in the first direction,
• in a cross-sectional view at a cut plane parallel to the first direction, the first seal member comprises a first base part and a lip part standing from the first base part and contacting the cylinder, and
• in the cross-sectional view, the second seal member comprises a second base part and does not comprise a lip part standing from the second base part.