An axial impeller has blades formed from sheet metal blanks that are configured from taking a desired impeller blade and mathematically “unwinding” the blade to its flat counterpart. Preferably, the impeller blade is formed from a single rolling operation. The result of a thin, elongate blade, preferably having a trailing edge that defines a helix with rearwardly skewed, forwardly raked blades, provides an efficient impeller having good anti-ragging properties.