Forstner bits feature continuous rounded edges for smooth cutting with minimal tearout. Sawtooth bits feature serrated edges for cutting harder materials such as end grain. Sizes 22mm and smaller are Forstner style Sizes 25mm and above are Sawtooth style. Bits up to and including 28mm have an 8mm shank Bits from 32mm to 54mm have a 10mm shank. Metric sets include bits of following approximate sizes (accurate to +/- 0.5mm): 6mm 10mm 12mm 16mm 20mm 22mm 25mm 28mm 32mm 35mm 38mm 40mm 45mm 48mm 50mm 54mm Note: The plastic case provided may show Imperial sizing, but the bits are true metric sizes and reflect the size printed on the bit itself.