3mm 5pcs Lapidary Glass Sintered Diamond Core Drill Bits

Sintered Diamond Core Drills made with our exclusive metal bond developed for high strength and longevity，metal bond diamondcore drills are the finest core drills manufactured in the world. Diamonds held in a metal matrix bondfor core drilling glass, alumina quartz, ruby yag, siliconand other hard abrasive non-metallic ceramics.Sintered diamond drill bits are heavy-duty bits designed for long life.  Generally, sintered bits will have a long life of 20 to 30 or more times the life of a bonded diamond drill bit, if used properly.  The heavy-duty design provides long life when drilling in very hard materials such as porcelain tile, granite and hard stones.  However, there are some disadvantages.  Sintered core bits are much more expensive than nickel bonded diamond bits and the thick heavy-duty tip causes them to drill more slowly than thin-wall bonded diamond drill bits.