A pair of jigs for sharpening knives of various lengths. The opening of the clamp can be adjusted to suit different thicknesses of blade and the handle, which also locates the jig onto the tool rest, can be screwed in and out to control the grinding angle. Once one side has been sharpened the jig can be flipped over to produce the same angle on the other side. The SVM45 takes small knives down to a minimum of 70mm and the SVM100, which has a longer clamping capacity, takes knives either with longer blades (over 120mm) or very thin blades (such as filleting knives) where the increased support is an advantage. Can also be used for electric hand planer knives.