fuze

A fuze, sometimes spelled fuse, is a device attached to a munition or explosive charge to initiate detonation or activation. Fuzes govern when and under what conditions the explosive effect occurs, affecting effectiveness and safety. The term is most common in military contexts, but it can also be used for non-military arming devices that trigger pyrotechnic charges.

Impact (percussion) fuzes detonate on contact or sudden deceleration. Time fuzes delay detonation for a preset interval after arming. Proximity fuzes use radar, infrared, or other sensors to detonate near a target, reducing the burst distance. Base or tail fuzes position the detonator to ensure initiation at the correct phase of flight or impact.

Fuzes integrate safety and arming mechanisms to prevent premature detonation. After release, acceleration, rotation, or electronic signals typically arm the fuze, and a sensing condition triggers the explosive sequence.

Historical fuzes began with mechanical time-delay and percussion devices. Electrically powered and electronic fuzes emerged in the 20th century, enabling greater reliability and precision. Proximity fuzes widely deployed in World War II spurred advances in miniaturization and electronic sensing. Modern fuzes often use microelectronics, programmable timing, and advanced safety features.

Fuzes are used in artillery shells, bombs, grenades, and some demolition charges. Handling and disposal follow strict safety standards to minimize accidental detonation and environmental risk.