4400 18P Auger, 18D, 30L, 1.38Hex

Auger bit. Digs an 18 inch nominal diameter hole up to 18 inches deep. Heat treated, alloy steel wear parts are field replaceable.
1-3/8 inch female hexagon auger drive connection.
18 inch effective digging depth for planting balled-type trees.
19-1/2 inch cutting diameter when boring head is in new condition.