Widely Used: Our multi-purpose drill bits with sharp cutting edges for versatile drilling in drywall, brick, tile, wood, aluminum and sheet metal. Spear Tip Design Solid tungsten carbide tip can easily penetrate various materials and reduce chipping. Efficient Design: The triangular handle drill prevents slipping and allows the drill to be clamped and stabilized on the electric drill. The U-groove design allows for perfect chip removal throughout the blasting process. No broken edges, no jerking, low cutting resistance, high drilling speed, easy chip removal. Material: High quality tungsten carbide drill bit, which can prevent cracking and provide longer service life, strong and durable. 2-slot design for better removal of drill dust. Dimension: Multifunctional drill with 7 different sizes, 3mm/4mm/6mm (1/4"), 8mm ( 5/16"), 10mm ( 3/8", 12mm (1/2"). Warm Tips: The multifunctional drill bit is resistant to high temperature around 1000. The working time can exceed 1000 in the head, however, they will burn out. So it is necessary to add water when drilling in high hardness material. These bits can be used to load drill, hand drill, a bench drill, etc. Do not use the impact mode of drills or hammers.