LARGE chuck can hold bits from 1/2" to 3/4". Fits Models 400, 500 and 750 only.
Drill Doctor, Drill Bit Sharpener, Sharpens Drill Bits From 3/32" To 1/2" Diameter, Carbide, Masonry, High Speed Steel, Cobalt, In Coated, Split Points & Parabolic Twist Drill Bits, 118°ree. Angle Or 135°ree. Angle, Can Sharpen Up To 3/4" With Optional Chuck Model #SAO1751PA.