The Flat Beater is the ‘wooden spoon’ of the KitchenAid Stand Mixer. It is used for any gentle folding, slow and fast mixing, cutting/rubbing in, creaming or beating such as creaming butter and sugar, creaming egg yolks and sugar, combining flour mixtures, combining all-in-one cake and batters or gentle folding, ‘rubbing in’ shortening for pastry, beating of soft fruits and vegetables (rough dip or sauces and combining dough/pasta mixtures before kneading.
The KitchenAid Flex Edge Beater is a flat beater and spatula combined. It is used for creaming and beating; its action mixes/creams and wipes the sides of the bowl (i.e. creaming butter and sugar, combining cake and batter mixtures).