Premium Quality: Made from tungsten steel and heat treated for high hardness, sharp edge, high precision, smooth cutting, impact resistance, and high toughness. 5PCS Set: Includes 40mm, 45mm, 50mm, 60mm, and 70mm sizes. Suitable for drilling wooden products, spherical door push tips, drawers, plastic products, wood, plywood, and similar materials. Warm Tips: These are large-size drills over 40mm. For best results, use with machines that have good fastening performance, such as power drills, bench drills, vertical drills, or stand motor drills. When using a hand-held electric drill, it is recommended to secure the workpiece with a vise for better stability. Easy to Store: Each drill bit is individually packed in an oil-containing plastic bag to prevent rust. A plastic storage box is included to protect the drill bits and maintain sharpness.