The side of the keyway is the working face of locking elements. Key with keyway, there are 3 choices, loose connection, general connection, tight connection. And the first two kinds of coordination, may be "gap". Divided into two types of open and closed keyway, the open keyway means that the keyway is opened from the shaft end, that is to say, the keyway is connected with the shaft end or the shaft platform. For example, motor shaft keyway. Closed keyway means that both ends of the keyway are closed.