This report combines the results of two bending fatigue studies on butt-welded pipe: one on 1 ½ schedule 80 pipe and the other on 4 schedule 40 pipe.The main objectives of these two investigations are to extend the fatigue database of butt-welded pipe from Markls tests into the low cycle range (100 to 2,000) and to compare the measured fatigue strength with formulas developed by Markl on stress amplitude versus cycles to failure.