Quarry Duty Motors, also called Crusher Duty Motors, are heavy-duty TEFC motors built to start and drive high-inertia, shock-loaded equipment such as jaw, cone and impact crushers, screens, conveyors and mills. They deliver high starting and breakdown torque, often meeting or exceeding NEMA Design C, with heavy cast iron frames, roller bearings for belted drives and seals against abrasive dust and moisture. They are built for aggregate, mining and cement operations where downtime is costly.