Abstract: There is provided a multi-shaft kneading disc, kneading disc block, and a multi-shaft extruder containing the same. The kneading disc and each kneading disc in the kneading disc block having a disc shape with a central section defining an extruder shaft mounting bore and at least one lobe extending radially from said central section and having a crest end. The at least one lobe has a radius X which defines an outer diameter of the kneading disc. The central section has a radius Y which defines an inner diameter of the kneading disc. At least one other lobe extends radially from the central section and has a radius Z. The radius Z defines the outer diameter of at least one other lobe. The radius Z of the other lobe is equal to Y+⅞(X−Y) to Y+¼(X−Y).