Johnson Duramax 30MM Brass cutless bearings adapt equally well to strut and stern tube mounts and are often used efficiently as rudder stock and pintle bushings. Johnson Duramax 30MM Brass cutless bearings use a specially formulated oil and chemical resistant nitrile rubber that is bonded to the shell. Johnson Duramax Marine is the world’s largest supplier of marine bearings and each is made in the USA. Order your 30MM Bearing today. The measurements for the 30MM cutlass bearing are Shaft Size: 30MM Outside Diameter: 45MM Length: 120MM.