... we have had the proved qualities systemized, with 3 basic grades which are characterized by fast cutting, long life ... to fit exact machine/stone hardness/Country for higher match. Characters of each basic grade:-1. fast cutting: fast sharp ... , plate, abrasive, wheel-.polishing: pads, abrasive-.drilling: core drilletc. For all natural stone such as granite, marble, sandstone, limestone, travertine, lava ...