Long before the existence of chucks, catch plates have been used for used for the clamping of workpieces when turning at top speed. Even now use is often made of this simple but secure way of clamping. The advantage of a catch plate is that the workpiece remains very briefly on the shaft, which is very important for the load of the shaft and the ball bearings, in particular when turning heavy or eccentric pieces. Furthermore, these pieces may be attached with multiple screws. Catch plates are made mostly of steel or cast-iron. Because of its brittleness, aluminium is not suitable for this. The ONEWAY plates with an OW code are made from cast-iron. The FP coded plates are made from steel.
Since there is no thread in the OW2395 face plate, you need to order the SH0355 adapter separately.