Many fretting-prone contacts are surrounded by oils, although they are not intended to lubricate them. To study the fretting behavior of contacts whose edge is exposed to engine oil, self-mated 34CrNiMo6 +QT steel was employed with a large annular flat-on-flat contact. A displacement-controlled loading was tested in a range, encompassing stick and gross sliding. No stick-to-slip transition with displacement amplitude was observed up to a tangential-to-normal traction ratio of 1.6, compared to that of 0.5 in dry contact. Beyond that, a typical peak-to-stabilized friction curve was reached in oil with a steady-state value of roughly 0.4, lower than that of dry contact. Adhesive wear existed as the dominant wear mechanism, and the severity of adhesion increased with higher loading. •High traction ratio in slip-stick, even more than friction peak in gross sliding.•While high-level of traction ration, mild surface damage was seen in slip-stick.•Reduced and earlier friction peaks with displacement amplitude in gross sliding.•Higher tangential loading led to more martensite grain refining and strain hardening.•Formation of carbonaceous phases like graphite on fretted surfaces in gross sliding.