Piston pump, in particular high pressure fuel pump

The pump (18) has components e.g. inlet ports (20), outlet port (22), actuating device (30), and pressure sensor, attached laterally at a pump housing (34). The pump housing comprises a polygonal cross sectional shape i.e. hexagonal profile (39) with sectional side surfaces (40a-40f). The components are arranged in a region of the side surface. The housing (34) has a shape of a symmetric polygon i.e. hexagon, in cross section, and made of stainless steel. The component has a fluid connection and an electrical connection.