Animal food pellets are formed from moistened solids pressed through radial bores in a hollow cylindrical die by eccentrically mounted rollers rotating against the apertured die wall. The die is affixed to an annular support by a holder with at least one of the features; (a) a membrane is forced against the outer die surface by radial fluid pressure. (b) undercut apertures at end faces of the die are engaged by projecting locking members rotatable by fluid pressure through an angle, bringing a cross-bar into engagement with the surface adjacent the aperture. (c) interlocking concentric self-locking threads are provided directly or indirectly for the die and its holder.
