Abstract: A pelletising machine of the kind comprising an annular die having radial bores therethrough, and adapted to be rotated about its central axis, whereby material introduced into the centre of the die is extruded through the bores by the action of freely rotatable pelletising rollers which are closely spaced from the inner peripheral surface of the annular die, and having a door which can be hinged between an open position enclosing the die, there being a cut-off knife mounted on the end of a shaft extending through the wall of said door, characterised in that the shaft supporting the cut-off knife passes through a guide sleeve carried in a housing secured to the wall of the door, there being means to permit fine adjustment of the position of said shaft axially within said guide sleeve and means permitting said guide sleeve together with said shaft to be moved as a unit rapidly outwardly relative to said housing and returned inwardly to their initial position.