Edge defects are present in nearly all tools prior to edge prep. The defects are the result of die flash after pressing, EDM processing and grinding. Some of these defects are illustrated here. Although microscopic in size such defects lead to erratic tool performance and premature tool failure. These defects must be eliminated if one is to achieve optimum tool performance.
The tool edge preparation process, when administered properly, adds strength to the tool cutting edge, lengthens usable tool life, minimizes the propensity of the edge to chip, improves part quality and consistency, and enhances work piece surface finish. Some of the edge preparation options currently used by the tool manufacturer are up sharp (no edge prep after grinding), radius or waterfall hone shapes, T-Land (or K-Land), and T-land + hone. The most widely used edge preparation that exists in industry today is the radius and waterfall hone shapes. These edge preps are applied in a variety of sizes based on cutting tool size and application. Edge prep is not limited to application of indexable style tooling. It is required on most cemented carbide round tools, brazed steel shank tools, PCD and PCBN tools, and single/multiple edge cemented carbide form tools. While T-Lands (or K-Lands) are ground on to the tool edge, edge hones are applied to cutting tools in a variety of methods. These processes include vibratory honing, honing by hand with diamond stones, mass media honing, slurry honing, honing inserts with media impregnated rubber wheels, dry blasting, wet blasting, tumbling and brush honing with abrasive media impregnated filaments.
