The Delicate Material Drill Bits 40mm Diamond Drill Bits with M14 Thread are professional-grade tools designed for both wet and dry drilling in a variety of hard materials such as ceramic, porcelain, tile, granite, marble, and sandstone. These vacuum brazed (VB) diamond drill bits are engineered with VB technology, allowing them to drill with greater efficiency and have a longer lifespan on hard porcelain and stone. With their M14 thread connection, these diamond drill bits can be easily used directly on an angle grinder, making them convenient and versatile. They are suitable for both DRY and WET drilling, making them adaptable to all conditions. Whether you need to drill holes for water inlets, drains, or light points, these diamond drill bits are the perfect tools for the job. Compared to galvanized drill bits, these diamond drill bits have a much longer service life, lasting almost 10 times longer when dry drilling HARD PORCELAIN. Even when wet drilling, they can still drill many more holes. To ensure the longevity of these drill bits, it is important to follow the correct instructions for their use. Key Features: Vacuum brazed (VB) diamond drill bits for wet or dry drilling in hard materials M14 thread connection for easy use on angle grinders Suitable for DRY and WET drilling in all conditions Ideal for drilling holes for water inlets, drains, and light points Longer service life compared to galvanized drill bits Can drill many more holes even when wet drilling Professional-grade tools designed for delicate materials Easy to use and operate