After examining some recent Charpy energy–fracture toughness correlations, a mean-2 procedure (M2P) has been proposed for estimation of reference temperature, T0, from CVN tests alone and has been established through a correlative approach. The T0 estimate from the M2P is referred as, TQ-M2, and is obtained as the mean value of two different estimates discussed in the text. Simplicity, consistency and assured conservatism of the TQM2 has been demonstrated by comparison with measured T0 values for some new steels. For the larger conservative estimate, it is suggested to take the larger of the two and this, in most cases happens to be the simple estimate, TQ41b, and is the same as T41J (the 41 J Charpy energy temperature). The applicability of the M2P for irradiated steels has been demonstrated. A new two-parameter correlation for estimating fracture toughness from Charpy energy has been derived and this gives encouraging results for the steels discussed in this paper.
