Authentic Easy Wood Tools Ci4-NR Negative Rake Diamond Shaped Replacement Carbide Cutter for Easy Start, Mini, Mid, Full and Pro Size Detailers. Negative rake cutters were designed for turning man-made acrylics, resins, extreme hardwoods and end grains. They produce better finishes with less “grabs” which equates to less sanding. Authentic EWT cutters have the optimal 3G’s of Carbide - Grade, Grind, and Geometry. 1) The Right Grade: Carbide is basically a mixture of tungsten powder and cobalt that is fused together under high pressure and heat. The ratio of cobalt to tungsten and the size of the tungsten particles are referred to collectively as the ‘grade’. There are literally hundreds of conceivable grades and no ‘one grade’ of carbide is suited for all applications – whether wood cutting or metal cutting. The perfect combination of cobalt and grain size in all EWT carbide cutters yields a cutting edge that is both the keenest and the most durable grade for woodturning/resin available today. 2) The Right Grind: EWT grinds all of their cutters on super rigid CNC grinders to prevent micro chipping of the cutting edges. EWT uses the proper grit diamond wheels to produce the flattest, truest surfaces possible with minimal grinding scratches left on the surface. All the cutter surfaces are ground in the optimum sequence to bring the edge into keenness during the very last process, or once again, micro chipping of the cutting edges will occur if the proper sequence is not followed. 3) The Right Geometry: EWT grinds all their cutters to the correct angles and geometries specifically for woodturning. This produces an edge that cuts both cleanly and safely for all skill levels. Only when grade, grind, and geometry are in harmony will you have a cutting edge for high performance woodturning.