These may be useful on some thin plywood or balsa wood but for anything else you'll find yourself filing/sanding by hand after spending way too much time with these. Just a thick blade with a not so durable abrasive coating. The thick blade makes them ineffective for detailed scroll work and the abrasive coating fills fast. You could get as good, if not better, results from a nail file or the cheapest set of mini files from Harbor Freight.