Ball screw noise is virtually nonexistent because Series 2446''s ball nut uses plastic end cap ball returns. Ball screw is available in 12 or 16 mm dia with 10 mm pitch. Screws come with or without backlash in T5 and T7 accuracy grades. By eliminating external return tubes, nut body is small. Labyrinth seals and felt wipers protect ball nut from contamination.