BD-2 carbide auger bit is precision machined to closest possible tolerances for long, trouble-free service. It’s over-sized carbide cuts faster…never balls up…retains its original effectiveness far longer. The round tapered shank of the BD-2 drive fits into the drillhead without wedges or set screws. It can’t wobble or work loose. And, unlike blade-type drill heads, BD-2 bits are easily replaced with a hammer and a punch. Fits BD and D-P auger drill heads.