A fail-safe brake (also called a power-off brake or spring-applied brake) is designed to engage automatically when power is removed. In its natural state, strong springs apply clamping force to the disc or drum. Power—hydraulic, pneumatic, electromagnetic, or electro-hydraulic—is only used to release the brake for motion. If power fails due to an emergency stop, cable damage, or a site-wide blackout, the brake applies immediately to secure the load or hold the machine.
Use a fail-safe brake whenever uncontrolled motion could cause injury, equipment damage, or regulatory non-compliance. Typical applications include crane and hoist lifting mechanisms, wind turbine yaw and rotor braking, mine hoists, downhill conveyors (runback prevention), and elevator systems.
Fail-safe does not automatically mean “emergency stop capable” for frequent dynamic braking—always verify duty cycle, energy capacity, and thermal limits. When properly selected, fail-safe braking is a foundational safety philosophy, not an optional feature.