Several investigators have demonstrated empirical relationships between creep and rupture properties for various metals and alloys. We have examined empirical relationships between the rupture life and the minimum creep rate and the time to the end of steady-state creep (start of tertiary creep) for four heats of normalized-and-tempered Cr—1 Mo steel with different carbon contents. The primary objective was the determination of the conditions that affect the correlation. The following relationships were obeyed: andt2 = Fs tr , where t2 is the time to start tertiary creep, tr is the rupture life, is the steady-state creep rate, and C and Fs are constants. The primary micro-structural constituent (proeutectoid ferrite or bainite) of the matrix and the precipitates present in that matrix (before test or formed during test) played a significant role in the correlation of the data with the empirical relationships.