<div class="section abstract"><div class="htmlview paragraph">INDUCTION heating, the authors show, has been successfully applied to the hardening of many types of gears. Over a million transmission gears have been produced with its aid and thousands of induction-hardened final-drive gears and pinions are giving satisfactory field service.</div><div class="htmlview paragraph">It has resulted in lower costs (due to the substitution of carbon for alloy steel, fewer machining operations, and lower heat-treating costs) and improved quality (due to a lack of distortion and better stress distribution).</div><div class="htmlview paragraph">The first part of this paper, by Mr. Kincaid, covers the equipment and methods used in handling various gear jobs. Then Mr. Knowlton covers the engineering tests and service performance of various types of induction-hardened gears.</div></div>