The Granlund spirabore system is a broad and flexible cutting tool system for large hole drilling in steel, cast steel and cast iron. The system consists of springsteel toolholders, cuterheads in HSS with effective chip breakers and roller pilots.
Cutterheads are stocked in dimensions from diameter 32.0 mm to 100.0 mm, we manufacture up till diameter 200.0 mm on request. The dimension range is divided into seven groups and within each group there are several holders with different lengths and a range of different diameter cutterheads and pilots to choose from.
Compared to conventional job drills the drill system admits quicker tool change, higher chip removal ability (feedrate up till 0.6 mm/r), simple re-sharpening and the ability to reuse holders and pilots. In short, a more cost efficient method.