Strong MaterialThe garden auger bit head is made of premium manganese steel and the shank is made of A3 steel, durable and not easy to deform. against rust High EfficiencySpiral design ensures efficient digging and trouble-free soil dumping. Use a drill at low (slow) speed, then drill into the ground or suitable landscape, the auger bit easily digs a hole in seconds and works well even in the somewhat hard ground. Note: Not suitable for large rocks or solid rocks Suitable MachineBoth garden drill bits work great with any 3/8" or larger chuck drill. But better to use drills with 18V power or more (For the drill cordless at least 14V) in order to better digging experience and save labor time 2 Various SizesThis set contains two auger bits 40 x 220mm and 80 x 300mm. They are used to quickly dig a hole of 40mm/80mm in diameter, and 220mm/300mm in depth. It helps you to plant many different size plants, very useful to help you create a nice little garden Wide ApplicationThese spiral drill bits are the professional landscaper's ideal choice, well suited for planting bulbs, potted plants, vegetables, flowers, bare root trees and shrubs, cultivating soil, and mixing seeds. After using, always keep the drill bits clean in order to each best use