EMPLOYMENT: German self-destroying nose fuze used in the 2-cm Mauser (H.E.-ammu-nition). (See fig. 554.)

Over-all length: 1.063 inches.

Maximum diameter: 1.781 inches.

Threaded length: 0.250 inch.

Number of threads: 7 RH.

CONSTRUCTION: The steel body of the fuze has a metal closing disc at the nose which protects the striker from air pressure and it is threaded at the base to engage the threads of the projectile. A primer detonator is screwed into the base of the fuze.

Inside the fuze a shoulder on the firing pin bears against a split collar on the bottom and a percussion plunger on the top. The split collar is housed in a recess in the center of the fuze and is held together by a spiral brass ribbon. The percussion plunger in the up-per recess of the fuze is surrounded by a compressed spring bearing against the fuze body at the top and a shoulder on the plunger at the bottom. The shoulder on the plun-ger is grooved to house eight steel centrifugal balls. The balls are retained in position by a steel ring which increases in its internal diameter towards the top and is supported by the body of the fuze. There is a central hole in the fuze to permit the striker to reach the primer.

ACTION: Centrifugal force causes the steel balls to fly out into the enlarged portion of the retaining ring thus locking the percussion plunger and its compressed spring in place. Centrifugal force also loosens the brass ribbon permitting the split collar to be thrown free of the striker. Upon impact the steel balls are cammed back into their housing and the compressed springer aids in activating first the plunger and then the firing pin, the latter piercing the primer.

Whem impact does not occur before a certain length of time, the spring overcomes the decreasing contrifugal force and causes the balls to be cammed back into their housing again releasing the plunger so that it may force the firing pin into the primer.

Figure 554 – Z.Z. 1505