The International Atomic Energy Agency (IAEA) established a Coordinated Research Project (CRP) in 2013 on “Sodium properties and safe operation of experimental facilities in support of the development and deployment of sodium cooled fast reactors” (NAPRO) in order to promote an efficient collaboration between organizations involved in sodium cooled fast reactor (SFR) programmes at the national and international levels. This research programme was carried out from 2013 to 2018. Eleven organizations representing ten IAEA Member States participated in the NAPRO CRP while eight organizations contributed to the drafting of this handbook. The present publication is the technical report of the NAPRO project focusing on the collection of heat transfer and pressure drop (friction factor) correlations for sodium cooled systems