A helical-acting snap roll for a harvesting header having straight flutes which are free of a formed twist. The snap roll includes a plurality of elongated straight flutes that extend substantially the entire length of the snap roll but that are parallel misaligned with a central axis of rotation of the snap roll. A pair of opposing and counter-rotating snap rolls of the present invention chops and pulls crop stalks passing therebetween downward toward the ground while also creating a helical action such that the crop stalks are conveyed rearward. In one embodiment, at least a pair of straight portions acting as flutes are partially parallel aligned with one another along the length and one side of each snap roll.