FISCH Wave cutter Forstner bits have been seriously engineered. The bits are forged, before being CNC ground and then hardened meaning; accuracy and sharpness are a premium. The unique 'Wave' cutter design has many benefits compared to a more traditional Forstner. The serrated 'Wave' edge generates considerably less heat and allows cutting speeds to be increased with less effort needed to achieve each hole. These imperial bits have 3/8" shanks. Made in Austria. For the best results, use in a pillar drill.-bg