Grizzly H7653 Indexable Spiral Cutter Head, 6-Inch These cutter heads replace the standard straight-knife cutter heads on our grizzly jointers Each cutter head has four spirals with indexable four-sided carbide inserts that can be rotated four times for a new factory-sharp edge The 6-Inch and 8-Inch jointer cutter heads include cast iron pulleys bearing blocks and mounting studs