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. The surface with glossy black painted finish well protects the garden drill bits against rust High EfficiencySpiral design ensures the efficient digging and dumping of the soil without difficulty. 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 Sizes4*45cm Wide ApplicationThese spiral drill bits are professional landscapers ideal choice, well suitable for plant bulbs, potted plants, vegetables, flowers, bare root trees and shrubs, cultivate soil, and mix seeds. After using, Always keep drill bits clean for each best use