These are the BOMB zipline drill bits for poles. RR ties, trees, hard lumber, and anything you need to drill through when building your zipline. WoodOwl auger drill bits cut faster, cleaner, and longer. These allow you to use a cordless to drill through a fat, wet, treated, class 1 pole in a less than a minute. Expertise in the forging and honing of high-quality steel dates back in Miki City, Japan 2000 years ago. Miki City became the center of the folded steel industry in all of Asia. We carry most of the sizes and styles of auger bits for Zipline construction as well as Zip Line modifications in stock.