I bought two of these end mills and both tools failed at the cutting edge shortly after contact with the material. I was attempting to engrave 303 stainless steel at a very conservative feed and speed at a depth of cut of .010 and again .005 after the first tool failed. In both cases I used coolant. I suspect inferior carbide. The tool works well as a beveling tool in materials such as cold rolled materials, but on harder materials it does not have enough power to make simple engravings.