A dry calibration device for extruders, comprising: - a calibration head having a calibration duct in which an article of manufacture can be inserted, said calibration head further including: - a longitudinal extension axis (A); - a wall having: - an inner surface defining said duct ; and - an outer surface opposite to said inner surface ; - a heat exchange jacket placed in contact with said calibration head , said heat exchange jacket comprising - a thermally conductive element placed in contact with said outer surface and defining a contact surface with said outer surface , said contact surface extending without a break along said longitudinal extension axis (A); - suction means associated with said calibration duct ; wherein said suction means comprise a plurality of suction ducts made in the calibration head and in fluid communication with said calibration duct ; wherein said suction means further comprises two slots located on the heat exchange jacket and on opposite sides of the thermally conductive element 6; wherein said calibration head presents a plurality of cavities made on the wall of the calibration head and said two slots are in communication with said plurality of suction duct by means of said plurality of cavities ; and wherein said suction means also comprises a pair of further ducts each associated with a respective slot of said two slots and with suction devices, characterized in that : - the thermally conductive element is of one piece construction, and fully surrounds said calibration head ; and - the heat exchange jacket also comprises a support for the thermally conductive element , inside which support there is a channel for circulating cooling fluid or heating fluid, said channel surrounding the thermally conductive element . - a calibration head having a calibration duct in which an article of manufacture can be inserted, said calibration head further including: - a longitudinal extension axis (A); - a wall having: - an inner surface defining said duct ; and - an outer surface opposite to said inner surface ; - a longitudinal extension axis (A); - a wall having: - an inner surface defining said duct ; and - an outer surface opposite to said inner surface ; - an inner surface defining said duct ; and - an outer surface opposite to said inner surface ; - a heat exchange jacket placed in contact with said calibration head , said heat exchange jacket comprising - a thermally conductive element placed in contact with said outer surface and defining a contact surface with said outer surface , said contact surface extending without a break along said longitudinal extension axis (A); - a thermally conductive element placed in contact with said outer surface and defining a contact surface with said outer surface , said contact surface extending without a break along said longitudinal extension axis (A); - suction means associated with said calibration duct ; - the thermally conductive element is of one piece construction, and fully surrounds said calibration head ; and - the heat exchange jacket also comprises a support for the thermally conductive element , inside which support there is a channel for circulating cooling fluid or heating fluid, said channel surrounding the thermally conductive element . <EOS>