【EXQUISITE CRAFTSMANSHIP】Our diamond drill bits are made of industrial grade carbon steel and coated with nickel-plated coating to prevent corrosion. Fine workmanship, super wear-resistant and sharp. 【HIGH QUALITY DRILL BITS】Each hole is smooth and precisely surface treated, and the thick diamond coating on the top can provide excellent cutting force to achieve maximum cutting effect. 【THESE GLASS HOLE SAWS】These glass hole saws are arranged along the drill bit to facilitate the removal of chips and other particles during cooling water entry and drilling. Make the drilling process easier. 【WIDE APPLICATION】This glass drill bit set includes 15 different drill bits for different needs. It is used for drilling hard surfaces such as glass, wood, ceramic tile bottles, block pots, ceramics, slate, granite pumice, etc. 【NOTE】When cutting hard materials, be sure to keep the tool cool to avoid damage to the drilling and premature wear of the tool; Water lubrication is required when drilling,