Abstract: on the basis of the principle of superposition formulas for calculating the frictional temperature at any point on tile tool-chip interface have been obtained. These formulas have been tested by the author with experimental data given in hither to published literatures, and the result of testing shows that they are sufficiently accurate. These formulas are as follows; The general formula :for calculating the frictional temperature tit any point on the tool-chip interface is When the specific frictional force takes uniform distribution, the formula for calculating the frictional temperature at any point on tire tool-eltfp interface is and the Formula for calculating the average frictional terapelaturo is When the specific frlutional force takes triangle disteibution, the formula fore calculating the frictional tomperature tit any point on the tool-chip interfnco. Is and the fornwaln for calculating the avorngofrictional . Temperature is.