Irwin 4X Blue Groove Long Flat Wood Drill Bit

The Irwin Blue Groove 4X Long Flat Bit in 28mm x 400mm delivers exceptional drilling performance for very large diameter applications in timber construction. This substantial size is perfect for creating holes for 28mm copper pipe with generous clearance, 35mm plastic pipe, larger waste pipes, substantial conduit runs, and heavy-duty mechanical installations through deep timber members. With its robust 28mm cutting diameter and extended 400mm shank length, this bit is the professional's choice for the most demanding drilling applications through floor joists, deep wall cavities, and roof timbers. The patented Blue Groove technology features an advanced groove point and cutting edge that cuts cleanly through timber rather than scraping, delivering speeds up to 4 times faster than conventional flat bits. The parabolic scoop design maintains excellent chip evacuation even at this larger diameter, ensuring smooth, controlled operation throughout the drilling process. Engineered with a 10% larger diameter shank for superior strength and an improved 17° relief angle for efficient cutting action, this bit combines the speed of advanced cutting geometry with the durability demanded by intensive professional use.