When you mount your knife in the KJ-45 Centering Knife Jig, the knife self-centers in the jig, whatever its thickness or geometry. This means that the jig centers everything from the thinnest knives to knives with a thickness of up to 10 mm (7/16"). It also means that knife blades that taper off from back to edge and heel to tip are centered in the jig, providing symmetrical grinding on both bevels of the knife.