... than above two types.2. Series and CharacteristicsSMD 5190.With the most accordant crystal color, excellent controled shape, very good ... grinding and free-cutting tools, grinding wheels which work with medium loadSMD5130Comparatively regular crystal shape, high strength, containing ... normal super hard abrasive.SMD5111Most of the crystal are needle sheet shape, with good self-sharpness ability, can be ...