General description The Irwin 4X Blue Groove long flat bit is engineered for efficiency, featuring a patented groove point and cutting edge that allows it to cut timber four times faster than standard flat bits. Its parabolic scoop design enhances control and effectively removes wood chips. Technical specifications Bit diameter: 25mm Shank length: 400mm Increased relief angle: 12° to 17° Shank diameter: 10% larger than standard