Exactly what the difference is between a regular dough hook and a spiral one ,I have no idea because my regular dough hook has always had a spiral in it but I have a totally different brand of mixer (a Kenwood Chef). I know that mine had always looked the same way, more or less but you can't swap a beater between models of mixer unless both are made for the same mixer which is unusual. Usually there are bearings to take into account in the mixer and just as importantly, the shape of the bowl. It often varies from model to model and so do the beaters ,so if your bowl and mixer is only designed for one style of dough hook , that is all you can use.