Minimum metal mine

Typically, the only metal components are located inside the fuze mechanism which triggers detonation.

This is achieved by encasing the explosive charge in a plastic, wooden, or glass body, with metallic components limited to the few small parts in the fuze which can not easily be made from other materials, such as the spring, striker tip, and shear pin.

The firing pin is pushed down through a flexible plastic forcing-cone, which abruptly releases it on the other side at much higher velocity.

Alternatively, when the shear pin breaks, pressure on the fuze is transferred onto a plastic belleville spring which flips downwards, stabbing a non-metallic tapered pin (sometimes made from a glass ceramic) through a thin plastic membrane covering the vial of friction-sensitive pyrotechnic mixture.

Early examples included the German Glasmine 43, Schu-mine 42 and Topfmine used during World War II.