A crimping tool with a quick-change crimp head for sealing and electrically crimping electrical contacts to insulated wires. The crimping tool includes a base unit with a receptacle that is configured to actuate and removably and replaceably receive the quick-change crimp head. A crimping die holder body includes a plurality of crimp-seal and continuity-crimping dies. These dies are mounted for movement in the crimping die holder body between an open configuration and a fully crimped configuration. The crimp-seal dies have arcuate die faces that define a substantially closed generally cylindrical form when the dies are in the fully crimped configuration. Actuators are mounted in the base unit. The actuators are adapted to cause the dies to move in the body. A sensor system is configured to prevent the crimping tool from unintentionally repeating a crimping operation on the electrical contact, and to verify continuity-crimp depth of indentation.