Auger Bits, Extensions, Adapters, & SuppliesDouble flight bit details: 2" hex bit connection. Bits available from 4" to 36 diameter @ 48" long. Bolt on fab bit style teeth, easily replaced with different styles of your choosing. Double flight means the flight steel is twice the thickness of a standard auger bit. Adds strength and durability providing superior quality and reliability. Flight thickness @ 1 4". Shipping @ 14 30 days. Adapters and Extensions: Made with Grade 50 American Steel.