A screwdriver blade has faces formed on front and back sides of a shank. Each face has a drive surface extending from each side edge inward toward a longitudinal axis. Each drive surface is inclined relative to a plane containing the axis and bisecting each of the side edges. A thickness of the blade increases from the shank distal end. Each of the drive surfaces appears curved when viewed in a distal end view. Each of the drive surfaces extends from the shank distal end to a face proximal end. A central portion between each of the drive surfaces may also appear curved when viewed in a distal end view, or it may be flat. The drive surfaces and the central portion may be formed at a single radius of curvature. The central portion may have a increasing width from the distal end or it may have a constant width.