Portable Mesabi® Screen Plants Rugged from the main frame up, portable Mesabi® Screen Plants are designed specifically to provide durability and portability for your scalping and sizing needs.  Extra heavy duty options provide even more support to handle the toughest of jobs.  Perfect in front of large primary crushers, Mesabi® Screen Plants are available in standard and heavy duty options in sizes ranging from 4x8 to 6x16.