Onlay Clasp

• It consists of a rest that covers the entire occlusal surface, from which the buccal and the lingual clasp arms originate.
• Indicated when the occlusal surface of the abutment lies apical to the occlusal plane.
• The onlay rest serves as a vertical stop and helps in the establishment of an acceptable occlusal plane.

  If the onlay is prepared with chrome cobalt alloy and is opposed by natural teeth the occlusal surface should be constructed of acrylic resin or gold, if chrome alloy used, because of its extreme hardness will cause rapid wear of enamel.