High Alloy wear resistant "Super Steels" require harder abrasives than those commonly found in Japanese whetstones to quickly and effectively make new, flat edges and to remove burrs, generally making diamond stones a better fit. These steels perform best at coarser polishes and feel washed out and dull quickly with finer finishes.
We recommend either a medium -- 1000 to 1200 -- grit finish or coarser. Experiment with your knife and use to see which finish works best for you. Consider one side at 400 and the other at 1000 for instance. Monodiachrome on a cork strop is excellent for deburring stubborn, wear-resistant super steels.
Diamond sharpening stones do not need to be flattened. If you choose to use synthetic stones to sharpen super steels, diamond stone flatteners are best to quickly level out the widest range of stone grits. Some flatteners can leave behind large particulates on finer stones that can leave deep, unexpected scratches feel after use with your fingers to see if there are any malignant grit that needs to be picked off. After flatteneing fine stones use a nagura or second fine stone to smooth out the grooves left from the flattener.