Munitions Army Dwg 9209204 40mm Red Smoke

Type Classification:

M525: Std B AMCTC 3403 dtd 1965.


Point detonating M525 Series fuzes are of the superquick, delayed arming, impact type used with 60mm and 81mm HE cartridges and 81mm TP or WP Smoke cartridges.


The head of the fuze contains a spring-loaded striker, direct-acting firing pin, and a clockwork mechanism to delay arming for a safe distance from the muzzle of the mortar. The head is threaded into an aluminum body containing a cylindrical slider to position the detonator, and a booster lead charge. Positive safety is provided by a safety pin to be removed just prior to firing.


After removal of the pull ring and safety pin, setback from weapon firing causes the setback pin (not shown in illustration) to release a bore riding pin. The bore riding pin then contacts the bore of the mortar and is ejected as the

Delayed Arming Mechanism For Mortars

projectile leave the muzzle. Setback also releases the pallet and escape pinion wheel (not shown) to begin movement of the delayed arming mechanism. This movement withdraws the firing pin from a detent in the slider. The slider is then moved transversely in the fuze body by a compression slider spring, to align the detonator with the firing pin. The delayed arming occurs approximately 3 seconds afle. the round has left, the muzzle. Upon impact superquick action occurs from detonator through booster lead charge and booster charge to explode the projectile.

M525 and M525A1 differ in the design of the fuze nose, and in the pull and safety wires.

Tabulated Data:

Type PD


Thread size 1/2-12NF

Assembly Dwg. No 8800197

Difference Between Models:

Temperature Limits:

Refer to complete round for upper and lower limits.

Shipping and Storage Data:

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