Our plywood groove bits are designed specifically for routing grooves and dadoes for joints in plywood. That means they match the true thickness of plywood, producing tight, accurate joints. Use our 18,2mm (23/32") bit for 19mm plywood, 12,3mm (31/64") bit for 12,7mm (1/2") plywood and our 6mm for 6,35mm (1/4") ply. No gaps or sloppy joints, guaranteed. These money-saving 3-bit sets are available with 12,7mm (1/2") or 6,35 (1/4") shanks.