This SAE Information Report is provided as a advisory guide. Individual appalication discretion is recommended. The content has been presented as accurately as possible, but responsibility for its application lies with the user. The document covers the variables in the torque-tension relationship: friction, materials, temperature, humidity, fastener and mating part finishes, surfaces, and the kind of wrenching employed. Also described in this document is the torque management required to achieve correct fastener joint tightening. The thread fit of fasteners must be in accordance with Class 2A for external and 2B for internal inch threads.