GATCO Sharpeners- 10004 -Edgemate Diamond Knife Sharping System The person who demands the ultimate performance in a sharpening system demands diamonds. Diamonds can quickly hone the hardest steel. System sharpens plain and serrated blades The Ultimate Diamond system utilizes the GATCO ® exclusive knife clamp/angle guide to insure that all cutting tools can be easily sharpened to a precise razor-like edge.