Abstract: In a pressure die casting apparatus, a die locking device in which a locking member is pivotably mounted on a frame and is movable into a position opposing a die part mount to have the force on the die part in the casting operation act through the locking member onto the frame substantially in the direction of that force. Another die locking device employs a main cylinder and piston assembly and an auxiliary cylinder and piston assembly with the chambers of the two cylinders interconnected whereby actuation of the auxiliary piston locks pressurized fluid in the main chamber. A sprue ejector mechanism has a plunger movable in a tubular piston rod, the end of the plunger being threaded to a collar and held to the piston rod and a cap threaded to the end of the piston rod, all for precise adjustment of the plunger in the die cavity.