A drill bit for percussion rock drilling. An impact portion includes an impact surface for striking against rock in an impact direction. An engagement portion includes a holder configured to hold the drill bit axially in a drill head of a drill string, and a rotation engagement member configured to connect the drill bit with the drill head for rotating the drill bit. An anvil surface is directed opposite to the impact direction for receiving shock waves from a striker rod of the drill string. A flushing channel is configured to transfer flushing fluid to the impact surface. The holder and the anvil surface are inside a holder recess having an opening that is directed opposite to the impact direction. Also a drill string component, a system and a method.