EMPLOYMENT: Base fuze used on German 7.5-cm H.E. projectiles and 5-cm A.P. shells. (See fig. 607.)

DATA:

Over-all length: 1.781 inches (with tracer).

Over-all length: 1.563 inches (without tracer).

Maximum diameter: 1.063 inches.

Threaded length: 0.438 inch.

Number of threads: 6 LH.

CONSTRUCTION: The base of the steel body is threaded internally to receive a brass tracer container. The center of the body is threaded externally to engage the threads on the projectile. An aluminum adapter is screwed over the top of the fuze body. A booster, containing either pellets of lead azide, calcium silicide, and PETN wax or tetryl, is screw-ed into this adapter and is sealed by an aluminum cap.

A funnel-shaped washer secures a firing pin in the body of the fuze. The flash from the primer passes through the washer and a channel in the firing pin. The washer is separa-ted from the booster by a series of paper and gauze disk which delay the action of the fuze.

The primer holder is held away from the firing pin by a heavy brass shear wire.

ACTION: Upon impact, the primer holder moves forward shearing the shear wire and im-pinging the primer on the firing pin. The flash passes through the firing pin, the funnel washer, the paper and gauze disk, and into the booster. The booster then fires the shell.

Figure 607 – Bd.Z. f. 7.5-cm Projectiles (Small Cavity)