One of the most widely applied types of flexible couplings is an elastomeric design known as the jaw coupling. This design is characterised by two hubs, each having two or more thick, stubby protrusions around their perimeters, called jaws, pointing toward the opposing hub. These jaws mesh loosely when the two hubs are brought together. Filling the gaps between the jaws are blocks of elastomeric material, usually molded into a single asterisk-shaped element called a "spider". Just as coupling designs vary to satisfy different application criteria, so do the spiders in jaw-type couplings. The spider is the key determinant of the torque rating of each jaw coupling. It also can make a significant difference in the coupling's response to vibration, temperature, chemicals, misalignment, high RPM, space limitations and ease of installation or removal. Selecting the right type of spider is just as important as selecting the right type and size of coupling. For that reason, users
will benefit from a fuller understanding of the different spider constructions and materials available, when specifying new or maintaining existing couplings.

One of the most widely applied types of flexible couplings is an elastomeric design known as the jaw coupling. This design is characterised by two hubs, each having two or more thick, stubby protrusions around their perimeters, called jaws, pointing toward the opposing hub. These jaws mesh loosely when the two hubs are brought together. Filling the gaps between the jaws are blocks of elastomeric material, usually molded into a single asterisk-shaped element called a "spider". Just as coupling designs vary to satisfy different application criteria, so do the spiders in jaw-type couplings. The spider is the key determinant of the torque rating of each jaw coupling. It also can make a significant difference in the coupling's response to vibration, temperature, chemicals, misalignment, high RPM, space limitations and ease of installation or removal. Selecting the right type of spider is just as important as selecting the right type and size of coupling. For that reason, users
will benefit from a fuller understanding of the different spider constructions and materials available, when specifying new or maintaining existing couplings.