Texas Knifemakers Supply: Ceramic Heat Treat Racks (Pair of 2) Ceramic base and high temperature pins are rated for temperatures up to at least 2200 degrees Fahrenheit Removable pins are spaced approximately 5/8" apart and 3-1/2" high when set, allowing plenty of room for foil expansion Sold as a pair, so you can balance your knife blade upright during heat treatment, allowing for even heat circulation