A concave for an agricultural combine includes first and second frames and a threshing mat that includes threshing bars each including a separating grate. An engagement assembly non-destructively connects each of the threshing bars to the first frame, the threshing bars form openings therebetween for grain to pass through, the separating grate of each of the threshing bars extends across an adjacent one of the openings for separating grain from threshed crop material, and the separating grate of each of the threshing bars is fixedly connected to an adjacent one of the threshing bars. The engagement assemblies enable non-destructive removal of the threshing mat from the first frame, when the second frame is spaced apart from the first frame. The second frame restrains non-destructive removal of the threshing mat from the first frame via the engagement assemblies, when the second frame is juxtaposed to the first frame.
