Irwin Tools 3043011 WeldTec WeldTec Ship Auger Bit With WeldTec, 7/8 IN Bit Diameter, 17 IN Overall Length, 7/16 IN Shank Diameter, 12 IN Twist Length, Twist Flute, Quick Change Impact Shank, For Wood, Public Utilities, Electrical, Plumbing, Carpentry, Log Homes