Use: 20-mm porjectiles.

Over-all length (with gaine): 1 9/32 inches.

Over-all length (without gaine): 3/4 inch.

Maximum diameter: 23/32 inch.

Threaded length: 3/16 inch.

Number of threads: 5.

Construction: There are two versions of this fuze, differing only in the fact that one is of one-piece construction and the other is of two-piece construction, having an inner metal collar threaded to the body. Threaded into the base of the fuze is a gaine, above which is an air column sealed at the top by a closing disc.

Operation: There are no arming features in this fuze. On impact, the closing disc is crushed inward, compressing the air in the column and firing the gaine.

Figure 429 – 20-mm Model 3 Fuze.