These carbide indexable inserts are under TPG 221 triangular positive grinding 221 must have a corner radius of 0.010 / 0.015. One of them, received on a box with the label closed, doesn't have the correct corner radius, more like 223 (0.032 / 0.045). .Call the supplier for customer service in Canada, I have no idea what I was talking about without even explaining technical information. waste of time