Over-all length (with gaine): 3 3/16 inches.

Over-all length (without gaine): 2 3/32 inches.

Over-all length (without gaine): 2 3/32 inches.

Maximum diameter: 1 1/4 inches.

Threaded length: 9/16 inch.

Number of threads: 6, left-hand.

Construction: The fuze body is of two-piece brass construction, with the upper part threading (right-hand) into the lower. A housing, containing the firing pin and a movable primer, is press-fitted into a recess in the upper fuze body and suppor-ted by a shear pin. The firing pin and movable primer are separated by a coiled spring. The primer is held from the firing pin by a metal washer containing two ears 180° removed. These ears fit into longitudinal slots in the lower part of the firing housing and rest against the under-side of a shoulder in the upper fuze body. A selector for short delay or instantaneous ac-tion is located and extends across the lower fuze body. This selector consists of a solid brass cylinder, one end of which is slotted for external control. Passing through the cy-linder is a hollow flash channel for instantaneous action. Ninety degress removed and in the same vertical plane is a delay channel which intercepts the instantaneous channel. The gaine threads (left-hand) into the lower fuze body.

Operation: On impact the shear wire is broken and the lower part of the firing-pin hous-ing is driven down into a recess in the upper fuze body, thus freeing the primer to move forward onto the firing pin. The primer flashes through the selector switch to the explosi-ve train.

Figure 326 – Type 100 Instantaneous-Short-Delay Fuze.