a simplified method of making and sharpening tools used in electrical discharge machining to avoid the laborious process of making a master die , a plastic master , several graphite blocks , a steel cutting tool and a final graphite block as a finished electrode . the present process uses a surfalloy process wherein metal is deposited on a prepared block to have a sharpness characteristic equal to that of a finished steel tool . thus , new tools can be made in about one hour where previous steps required about 90 hours .