General description The Irwin Blue Groove 4X Flat Bits feature a patented groove point and cutting edge that allows for cutting rather than scraping timber, making them 4 times faster than standard flat bits. The parabolic scoop design optimizes control and efficient removal of wood chips. Technical specifications Diameter: 40mm Length of shank: 152mm Increased relief angle: 17° (from 12°) Shank diameter: 10% larger than standard for added durability Other information 1 x IRWIN® Blue Groove 4X Flat Bit 40 x 152mm