High-quality multi-function drill kit made of tungsten carbide, not rust, prevent the drill bit from cracking, has a longer service life than the average steel drill bit, and is . Excellent drill bit makes drilling easier, less labor-intensive, and works at minimal pressure. The process design of the spiral drain groove can chip removal, effectively prevent the retention of accumulated chips and improve work efficiency. The spear tip is designed with a sturdy hard alloy tip that easily penetrates a variety of materials. The custom triangular tip prevents slipping during punching and is easy to install. Normal impact drills, electric drills and drill bits can be installed and used. Assorted Size for purposes, to meet the of your work. The masonry drill bit set easily penetrates a variety of materials such as tiles, glass, hard plastics, cement concrete, brick walls, wood, and reduces cracking. Materials with higher hardness are better for use with water. colour:blue Material:alloy Package Contents: 20 x 3mm Drill Bits 20 x 4mm Drill Bits 20 x 5mm Drill Bits 20 x 6mm Drill Bits 10 x 7mm Drill Bits 10 x 8mm Drill Bits 10 x 10mm Drill Bits 10 x 12mm Drill Bits 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.