7 MACHINE PARTS, NAMELY, HYDRAULIC CYLINDERS, HYDRAULIC NORM CYLINDERS, HYDRAULIC STANDARD CYLINDERS, HYDRAULIC CYLINDERS WITH PROXIMITY SWITCHES, HYDRAULIC CYLINDERS WITH DISTANCE MEASUREMENT MECHANISM TO DETERMINE THE POSITION OF THE PISTON IN THE CYLINDER, BLOCK CYLINDERS, CIRCULAR BLOCK CYLINDERS, FLANGE CYLINDERS, SHORT-STROKE CYLINDERS, CUBE CYLINDERS, SCREW-IN CYLINDERS, DOUBLE-PIPE CYLINDERS AND HYDRAULIC CYLINDERS WITH EXTERNAL GUIDES THE CYLINDERS MOVE IN; HYDRAULIC PUSHING UNITS; SWING TENSION CYLINDERS; ROTARY DRIVES USED FOR ACTUATING FLAPS OR VALVES WHEN MACHINE PLATFORMS ARE TURNED; CORE PULLER UNITS TO PULL CORES OUT OF CASTING MOLDS; AND FLUID PRESSURE BOOSTERS