Abstract: A jarring moulding machine having a table and impact receiving arrangement between the table and an anvil, which arrangement includes an annular impact member recessed into a surface of the anvil, and an impact insert of greater resilience than the impact member seated in an annular recess of step form at the inner periphery of the annular impact member. The top surface of the impact member projects slightly beyond of the anvil surface and the top surface of the impact insert projects slightly beyond of the top surface of the surrounding impact member so that the insert receives the impact before the impact member. The seating recess for the insert is undercut at the junction of its walls so as to leave a small clearance therebetween. The impact member may be of a polyethylene synthetic plastics material and the insert may be of rubbery polyurethane.