This publication has been developed under the Coordinated Research Project (CRP) entitled: Surveillance Programme Results Application to Reactor Pressure Vessel Integrity Assessment. This publication provides a summary of master curve fracture toughness test results on small surveillance type specimens of the IAEA reference material JRQ and other national steels from numerous laboratories around the world. These results were a key ingredient used in the development of the guidance given in IAEA Technical Reports Series No. 429, Guidelines for Application of the Master Curve Approach to Reactor Pressure Vessel Integrity. This publication has been written to allow utility engineers and scientists to directly measure fracture toughness and apply the results using the master curve approach for RPV structural integrity assessment.