If you are talking about proper terminal torquing, then the specific value will be listed and labeled for the respective device or equipment from the manufacturuer. There is not a standard value or table that I am aware of.
There is a table of tightening torques for various types and sizes of terminal screws/lugs in the Canadian Electrical Code, but the torque ratings are given in lbs-inches, not newton-meters (Nm).
In the 2003 code hand book there is a table on page 45, actually starts on page 44 under 110.14
Electrical Connections.
The downside is it is in #-in not Newton-meters/N-m.