Sheartak Spiral Cutterhead for WOLFENDEN 6" Jointer 38 Carbide Inserts on 6 spirals Woodworkers are now retrofitting spiral cutterheads to their old planers, and jointers for the following advantages. * Smoother Finish with helps reduce tear-out, including on difficult grain. Each knife sits at a slight angle and produces a shear-cut. Spiral cutterhead planes board in a staggered way which is much better than a single straight cut. The combined shear and staggered cut helps reduce tear-out, including on difficult grain and leaves a glossy surface finish on even highly figured hardwood. * Noise is hugely reduced as the spiral cutterhead allows a few knives to cut in a staggered way. * More than carbide inserts generally stay sharp significantly longer than HSS knives the life use of high-speed steel. The 15x15x2.5mm inserts are made of sintered tungsten carbide which is much harder than high-speed steel. Each insert has four edges. * Easy to change. The knives are precision ground to a tolerance of +/-0.0004" or +/-0.01mm and are interchangeable. Loosen the screw, rotate 90° for a new edge, and tighten the insert in minutes. * Dust extraction is easier. The spiral cutterhead produces thinner and shorter chips. * Low cost to use. Spiral cutterheads produce a smoother finish, reduce or eliminate sanding work, and don't require sharpening, your product will pay for itself in a very short time.