Irwin Power Drill I-100 Auger Bits 5/8 in. Dia. x 7.5 in. LPower Drill I 100 Auger Bits Features: Solid center design provides extra rigidity while boring Wide lands keep the bit straight as it bores through the hole. The flutes are ground behind the lands to funnel chips to the inside of the bit and away from the outside diameter, producing a faster, cleaner cut Single spur cutting edge scribes the circumference of the hole for a smoother finish Coarse screw point provides fast boring in hard and soft woods