RNK111
https://www.rnktools.com/products/end-mills-for-graphite.html
Diamond Coated End Mills for Graphite
Due to the graphite material's high abrasiveness, brittleness, graphite chip formation of intermittent influence, in the graphite machining process, the tool surface in the alternating cutting stress and cutting impact, easy to early breakage, rapid wear or even breakage failure, so graphite machining with the tool required to have a high resistance to abrasive particle abrasion and impact resistance.