An annular rotary knife blade (300;2300) for rotation about a central axis of rotation in a power operated rotary knife (100;2000), the annular rotary knife blade (300;2300) comprising: a body (310;2310) and a blade section (360;2360) extending from the body (310; 2310), the body (310;2310) and the blade section (360;2360) being radially centered about the central axis of rotation; the body (310;2310) including a first end (312;2312) and a second end (314;2314) spaced axially below the first end (312;2312) and an inner wall (316;2316) and an outer wall (318;2318) spaced radially apart, the outer wall (318;2318) of the body (310;2310) including an arcuate surface (319;2319) being convex radially outward with respect to the central axis of rotation, the arcuate surface (319;2319) including an upper region and a lower region, the upper region of the arcuate surface (319;2319) being axially closer to the first end (312;2312) of the body (310;2310) and the lower region of the arcuate surface (319;2319) being axially closer to the second end (314;2314) of the body (310;2310); the body (310;2310) further including a driven gear (340;2340) having an upper end and an axially spaced apart lower end and comprising a plurality of gear teeth, the plurality of gear teeth of the driven gear (340;2340) extending axially downwardly from the first end (312;2312) of the body (310;2310) and extending radially through the outer wall of the body (310;2310), the plurality of gear teeth including outer surfaces comprising at least a part of the upper region of the arcuate surface (319;2319); the outer wall (318;2318) of the body (310;2310) further including a first bearing surface (322;2322) for rotatably supporting the annular rotary knife blade (300;2300) for rotation about the central axis of rotation, the first bearing surface (322;2322) including an upper bearing face (324a;2324a) in the upper region of the arcuate surface (319;2319) and a lower bearing face (324b;2324b) in the lower region of the arcuate surface (319;2319), the outer surfaces of the plurality of gear teeth comprising at least a part of the upper bearing face (324a;2324a) of the first bearing surface (322;2322); and the blade section (360;2360) extending from the second end (324;2314) of the body (310;2310). a body (310;2310) and a blade section (360;2360) extending from the body (310; 2310), the body (310;2310) and the blade section (360;2360) being radially centered about the central axis of rotation; the body (310;2310) including a first end (312;2312) and a second end (314;2314) spaced axially below the first end (312;2312) and an inner wall (316;2316) and an outer wall (318;2318) spaced radially apart, the outer wall (318;2318) of the body (310;2310) including an arcuate surface (319;2319) being convex radially outward with respect to the central axis of rotation, the arcuate surface (319;2319) including an upper region and a lower region, the upper region of the arcuate surface (319;2319) being axially closer to the first end (312;2312) of the body (310;2310) and the lower region of the arcuate surface (319;2319) being axially closer to the second end (314;2314) of the body (310;2310); the body (310;2310) further including a driven gear (340;2340) having an upper end and an axially spaced apart lower end and comprising a plurality of gear teeth, the plurality of gear teeth of the driven gear (340;2340) extending axially downwardly from the first end (312;2312) of the body (310;2310) and extending radially through the outer wall of the body (310;2310), the plurality of gear teeth including outer surfaces comprising at least a part of the upper region of the arcuate surface (319;2319); the outer wall (318;2318) of the body (310;2310) further including a first bearing surface (322;2322) for rotatably supporting the annular rotary knife blade (300;2300) for rotation about the central axis of rotation, the first bearing surface (322;2322) including an upper bearing face (324a;2324a) in the upper region of the arcuate surface (319;2319) and a lower bearing face (324b;2324b) in the lower region of the arcuate surface (319;2319), the outer surfaces of the plurality of gear teeth comprising at least a part of the upper bearing face (324a;2324a) of the first bearing surface (322;2322); and the blade section (360;2360) extending from the second end (324;2314) of the body (310;2310).