The Irwin Blue Groove 4X flat bit have a patented groove point and cutting edge. The cutting edges cut the timber 4 times faster, without scraping. The parabolic scoop optimises control and removal of wood chips.

These flat bits have an increased relief angle from 12° to 17° . The large shank is 152mm in length and 10% larger in diameter for added durability.

The Irwin IRW10502817 Blue Groove 4x flat bit has the following specific dimension:
Diameter: 26mm