Abstract: Described are substrates for magnetic media which have excellent surface properties as prepared directly from a slot drawdown glass sheet forming process. The substrate blanks cut directly from the glass sheet, as drawn, require little or no surface treatment for use as substrates for magnetic media, particularly hard disk drives. Also described are methods for preparing such substrates and methods for preparing magnetic media therefrom. Further described are the substrates and magnetic media prepared by such processes.

Abstract: To shorten the processing time in modern plants for cutting away pieces or sections from a continously moving endless material, e.g. a glass strip, one after the other by flying cutting the cutting bridge carrying the cutting device (6) is accelerated until at a speed within a predetermined tolerance range of the feed speed of the continuously running endless material. Then the cutting bridge speed is synchronized for each piece or section to be cutaway and the cutting away of each piece or section takes place after the synchronization. To attain a very high precision cutting the spacing of the front cut edge formed when the previous piece or section is cut away from the cutting device is measured by means of an image-taking device (7) prior to cutting away of the next piece or section. Then the measured spacing is compared with a set value for the spacing and the speed of the cutting bridge is synchronized or fine tuned according to the comparison prior to cutting away the next piece or section.