The invention is a cutter head (A) of the foldable type and divided in portions, comprising a fixed or movable centre portion (A1) and one pair of lateral movable portions (A2, A3). Each one of said portions (A1, A2, A3) comprises a frame (F1, F2, F3), a segment of the cutting unit (B1, B2, B3) and a segment of the feed auger (C1, C2, C3), wherein each one of said auger segments (C1, C2, C3) in turn is constrained to the corresponding frame (F1, F2, F3) in an oscillating manner.