This International Standard specifies a method for measuring the Palmqvist toughness of hardmetals and cermets at room temperature by an indentation method. This International Standard applies to a measurement of toughness, called Palmqvist toughness, calculated from the total length of cracks emanating from the corners of a Vickers hardness indentation, and it is intended for use with metal-bonded carbides and carbonitrides (normally called hardmetals, cermets or cemented carbides). The test procedures proposed in this International Standard are intended for use at ambient temperatures, but can be extended to higher or lower temperatures by agreement. The test procedures proposed in this International Standard are also intended for use in a normal laboratory-air environment. They are not intended for use in corrosive environments, such as strong acids or seawater.