Sharpening with diamonds results in the finest, sharpest edges and DMT® products are the finest Diamond Sharpening products available – Worldwide. What does the "DMT® Difference" mean? Simply put, DMT® has done only one thing since 1976 – innovate and build the world’s best diamond sharpeners. Whether in continuous diamond surface or our trademark interrupted "polka-dot" pattern – don’t accept imitations. Frequently Asked Questions about DMT and Diamond Sharpening. Shop DMT Specials and Kits