A4.0 4.0mm[5/32″] Carbide Sharpening Burr – Sharpens 3/8 Lo Pro and 1/4 .050[1.3mm]

New carbide burrs for sharpening a chainsaw chain! Spiral single cut fluted shape – available in 9/64″[3.6mm], 5/32″[4.0mm], 3/16″[4.8mm], 7/32″[5.5mm]. How do they work? Not sure – first trials seem to show they take less than a diamond stone or certainly less than the coarse version. They fit nicely in your standard Dremel type tool [Note there is no thread on these to fit the Granberg grinders].