Carbide is very hard. Use cautiously and do your research about what material you are using it against. Carbide is not intended to be used on soft metals like aluminum. The engine block shown in video is cast iron. There are many ways to remove gasket material that is left over, one of the easiest, fastest safest and most effect method is by using a carbide tipped scraper that is specifically designed to remove hardened gaskets. I have found this method to be much better than any razor blade method. #diymechanic #mechanic #gasket #enginerebuild