These cast iron faceplates, made by Oneway Manufacturing, have specially designed ribs and a 1/4'' thick rim to make them as rigid as possible, even under heavy loads. They also have numerous holes to give you plenty of options as to where and how many screws to use when securing the workpiece. The holes are large enough for a #10 sized screw. Each faceplate has a hole on its edge for the tommy bar (included) that is used for removing from the lathe. We have these faceplates available in a 4'' size with 9 holes or a 6'' size with 24 holes.