a hard disk drive with a multiple disk stack normally utilizes disk separator plates near the disk surfaces to reduce wind induced vibrations in the disks and the read / write heads . the manufacturing methods currently used to make these separator plates , metal casting and machining , or injection molded plastic , or extruding and machining , or cold forging tends to be expensive and creates unwanted weight and bulk without the desired precision . stamping disk separator plates from metal provides exceptional dimensional control at reduced cost , but cannot readily provide the thicknesses required . stamping and extruding the offsets , or stamping and folding the offsets , is a manufacturing process that provides the required dimensions for the offsets , and dimensional control and reduced cost .