Fatigue crack propagation tests under a high stress intensity range have been carried out on a low alloy structural steel BS 4360 Grade 50B. Crack growth rates ranging from about 10‐5mm/cycleto over 0.1mm/cyclehave been recorded. Fatigue tests took on three kinds of control modes to achieve vastly different loading histories. Two specimen geometries which have markedly different yielding constraints and slip line field patterns have been employed. These tests aim at examining the ability of various fracture mechanics parameters to give a unifying quantitative correlation of fatigue crack growth rate from predominantly elastic to elastic‐plastic regimes. An effective cyclic‐J integral with crack closure being taken into account has been shown to be able to rationalize quantitatively the growth data under the different conditions investigated.