A single-use injector comprising a housing (200) accommodating a mechanical spring energy reservoir (50), a cylinder/piston unit (100), a piston-actuating ram (60) and a trigger unit (80), the spring-loaded piston-actuating ram being supported on the housing via support rods (240) or draw hooks (250) and each contact zone between an individual support rod or draw hook and the piston-actuating ram representing a wedge gear pairing that forces the respective support rod or draw hook radially outwards. The housing of the injector consists of a thin-walled sheet metal part. Said sheet metal part has at least two limbs (220, 250) arranged parallel to each other. The sheet metal part has at least two pressure bars or at least two draw hooks the free ends of which are bent in an angular fashion to define a supporting section for the piston-actuating ram.
