This part of ISO 7267 specifies a method for the determination of the apparent hardness of vulcanized rubber roller covers, expressed in international rubber hardness degrees (IRHD). The method is similar in principle to the methods used for the determination of the hardness of rubber vulcanizates in ISO 48, ISO 1400 and ISO 1818 in that it consists essentially of measuring the depth of penetration of a spherical indentor operating under a specified force. The apparatus used is similar to that described in ISO 48, ISO 1400 and ISO 1818, differing only in that the base is designed specifically for application to roller covers and similar curved surfaces.