This paper reports two series of fatigue tests on reinforced concrete beams. In both series, 8-in.-wide by 14-in.-deep beams were reinforced with one No. 8 bar. The American-made bars used in the first series had crescent-shaped transverse lugs that did not merge into the longitudinal ribs. The European-made bars used in the second series also had inclined transverse lugs that did not merge into the helical longitudinal ribs. Test results for the 14 beams in the first series and 12 beams in the second series indicate that orientation of the longitudinal ribs had little effect on the fatigue strength of these reinforcing bars. Furthermore, their fatigue strengths were comparable to fatigue strengths determined from previous tests on several different types of American-made bars with transverse lugs that merge into the longitudinal ribs. The geometry at the base of the lug appeared to have a significant influence on fatigue strength.
