PREMIUM QUALITY: This Diamond Drill Bit Set is crafted from High-Speed Steel and designed with a thick diamond coating. This tough composition makes the drill bits resistant to corrosion and enhances durability. Each bit stays sharp and can easily drill multiple holes, offering extended utility and precision. BIT DIMENSIONS: Each Hole Saw Bit in the set comes with an optimal dimension - 0.24inch/6mm Hole Diameter, up to approx 30 mm Drilling Depth, 51 mm Total Length, and 5.5mm Shank Diameter. These details maximize the utility of each bit and ensures the maximum number of revolutions: 800/minute. ADVANCED DESIGN: These drill bits are designed with clearance holes to improve efficiency. The side hole lets cooling water in, reducing the risk of overheating, while also allowing chip debris to escape, making your drilling process smoother and more comfortable. COMPATIBILITY AND VARIETY: This bit set is versatile, perfect for drilling different materials. You can use them on glass, tiles, porcelain stoneware and, granite slabs among others. Our drill bits are compatible with diamond tipped drill bits from any brand, offering wide-ranging adaptability. INDUSTRY-STANDARD TIP: While drilling, start at a 45-degree angle to the surface and progress to a 90-degree angle once the hole starts to form. Remember to use water to cool the drill bit when in use; this will prolong the life and maintain the sharpness of the drill bit. color:silver Material:metal Package Contents: 20 x drill Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.