A power tool (30) comprising a tool carrier (34) for mounting an impact tool (36). The tool carrier has a base member (38) aligned with an operational axis. The base member has a head end (40) for receiving impact energy, a foot end (42) at an opposite end of the tool carrier, the foot end being provided with a tool mount (44) configured to transmit the impact energy to the impact tool, and a casing engagement feature (46) provided between the head end and foot end. There is also provided a first casing module (50), at least part of the tool carrier being located within the first casing module. The casing module is provided with a tool carrier engagement feature (52) complementary in shape to, and for interlocking engagement with, the tool carrier casing engagement feature. This prevents rotation of the tool carrier relative to the first casing module around the operational axis, and permits relative movement between the tool carrier and the first casing module along the operational axis.