Material Heavy duty garden drill bits are made of cold rolled steel. High quality cold rolled steel material, strong and durable, not easy to deform. The surface has glossy black paint finish, which can well protect the garden drill bit from rust. High-efficiency auger design ensures efficient digging and dumping of soil without difficulty. Using a low (slow) drill speed and then drilling into the ground or suitable landscaping, the auger can easily dig a hole in seconds and works well even in somewhat hard ground. Note: Not suitable for large boulders or solid rock Machine Decent Both garden bits will work with any 3/8" or larger chuck bit. 2 Miscellaneous sizes This set contains two drill bits 40 x 220 mm and 80 x 300 mm. They are used to quickly dig holes with a diameter of 40mm/80mm and a depth of 220mm/300mm. It helps you grow many plants of different sizes and is ideal for helping you create a nice little garden. For potted plants, vegetables, flowers, bare root trees and shrubs, till the soil and mix in the seeds. After use, always keep the bit clean for best use every time This garden auger set is perfect for planting, seeding, trees, shrubs, deep tillage, concrete mix, potting soil, irrigation ditches and more. This ground drill also allows you to easily dig pole holes, and even take it on vacation to drill a hole in the sand to attach a parasol. It will be your good helper. Note: Keep the auger to remove dirt and debris when not in use.Note: The data is all measured manually, please allow 1-3cm error, due to the light and display difference, there will be a certain color difference, the actual object received shall prevail.Note: The data is all measured manually, please allow 1-3cm error, due to the difference in light and display, there will be a certain color difference, the actual object received shall prevail.