Irwin Tools Irwin Industrial Tools 49913 I-100 13/16-Inch Auger Bit is $12.38 at Amazon, down from the store's own list price of $20.77. That's 40% off ($8.39 less). We last checked this price on Nov 10, 6:08 AM ET. Prices at the store can change at any time, so check before you buy. Brand: Irwin. Type: Power tools. Picked for all trades and Carpentry & Framing.