35mm, 40mm, 55mm, 68mm, 4pcs per set.
Dry Use Vacuum Brazed Diamond Core Drill Bits Set for Porcelain
|Vacuum Brazed Technology
|1. Vacuum Brazed Diamond Core Bits are very aggressive ideal for drilling ceramic and porcelain tiles along with granite, marble,and stone with super high precision while leaving smooth edges with minimal chipping.
2. Vacuum brazed technology is superior to electroplating in that the bits last much longer than electro-plated diamond bits.
3. They can typically drill more than 30 holes although life is dependent on type of material.
4. You can expect each bit to last dozens of holes drilling marble and similar stones.