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. Either way, this action causes a flash of flame that triggers the detonator and initiates the adjacent booster which in turn detonates the main explosive filling.
Alternatively, when the shear pin breaks, pressure on the fuze is transferred to a plastic Belleville spring which flips downwards, stabbing a non-metallic tapered pin (sometimes made from glass ceramic) through a thin plastic membrane covering the vial of friction-sensitive pyrotechnic mixture. Either way, this action causes a flash of flame that triggers the detonator and initiates the adjacent booster which in turn detonates the main explosive filling.