Locking rings are made of anodised seawater resistant aluminium 6082 (AlMgSI1) and contain stainless steel set screws to achieve a perfect locking on the shaft. Its advisable to pre-drill the rudder shaft a couple of millimetres for the best security. Locking rings are used above the top bearing to prevent the rudder from sliding out of the vessel. Locking rings can also be used underneath the top bearing to prevent a light rudder from floating up. Between a locking ring and the bearing we always supply a delrin ring for a smooth rotation. For super smooth running applications we can supply a delrin ring with a ball race.