... ,refractory materials and reinforced concrete and so on Diamond Finger Router Bits are used for drilling all kinds of stones,glass,ceramics ... materials and reinforced concrete and so on ,with high efficiency,long life and standard drill hole. stone drills1, Used for : all ... --200mm.M14,5/8"-11 Connection3,Feture:fast cutting and long life4,MOQ:50pcs5,Payment : T/T6,Packing : Carton7,Delivery time ...