Abstract: A threshing cage for a grain combine has a frame with permanent and removable panels. Each panel is a semi-circular arc which extends between adjacent frame members to form a cylindrical shape. Each panel has an arcuate rib on each axial end and a pair of axial supports which joins them together. A perforated screen extends between the ribs and axial supports. The panels are pivotally mounted on the frame members and rotated into a locking position with panel levers. The panel levers have a cam member which pivotally engages a mating slot in an adjacent frame member. The panels also have side arc clamps for locking their ribs to adjacent structural support members.