The invention relates to a single-use injector comprising a housing(200) accommodating a mechanical spring energy reservoir (50), acylinder/pistonunit (100), a piston-actuating ram (60) and a trigger unit (80), the spring-loadedpiston-actuating ram being releasably supported on the housing. The housing oftheinjector consists of a thin-walled sheet metal part (201). Said sheet metalpart has atleast two limbs (20). Each limb has a bent retaining element (221) or a recesson itsfree end. The limbs are elastic flexural beams the center sections of whichare bent inthe shape of a z or an s to define a supporting section (231) for the piston-actuatingram. The contact zone between an individual supporting section and the piston-actuating rod represents a wedge gear pairing that forces the respective limboutwards.
