M564 fuze
Contents
M564 – mechanical time fuze with impact action
Fuze M564 an American high-explosive fragmentation (HE), mechanical time super-quick (MTSQ) clockwork fuze with dual-purpose impact and remote (time) action, used for 105 mm and 155 mm artillery projectiles.
Technical specifications
- weight: - 907 g;
- overall length: - 12.7 cm;
- visible length - 7.62 cm;
- fuze thread - 212-UNS-1A;
- fuze arming during firing — from the muzzle: - 66 m
Usage notes
Warnings:
Fuzes manufactured before January 1970 must be set to 90 seconds if only impact action is required.
Fuzes manufactured from January 1970 can be set to “S” or “90 seconds” if impact action is required. However, current doctrine provides that all M564 fuzes, regardless of manufacture and date, must be set to 90 seconds if impact action is required.
Premature functioning is possible when firing in rain. To avoid accidental functioning, never drop, roll or strike the fuze.
Difference in the remote-fuze settings of the M564 and M520A1
| M564 | M520 – increment correction |
| from | to |
| 2.0 | 2.2 | 0.2 |
| 2.3 | 5.9 | 0.3 |
| 6.0 | 9.7 | 0.4 |
| 9.8 | 13.5 | 0.5 |
| 13.6 | 17.3 | 0.6 |
| 17.4 | 21.1 | 0.7 |
| 21.2 | 24.9 | 0.8 |
| 25.0 | 28.7 | 0.9 |
| 28.8 | 32.5 | 1.0 |
| 32.6 | 33.3 | 1.1 |
| 36.4 | 40.1 | 1.2 |
| 40.2 | 43.9 | 1.3 |
| 44.0 | 47.7 | 1.4 |
| 47.8 | 51.5 | 1.5 |
| 51.6 | 55.3 | 1.6 |
| 55.4 | 58.0 | 1.7 |
Fuze Setting
Setting the fuze:
The fuze is screwed into the fuze socket of the projectile and tightened with a wrench
Setting for remote (time) action:
It is set by turning the time-setting scale (in the direction indicated by the arrow on the fuze body), graduated from 2 to 100 seconds, until the required numerical index coincides with the mark on the body.
Setting for impact action:
If impact action (fragmentation action) is required (set the setting scale to the “90 seconds” position).
The fuze will also function on impact (the fuze will be initiated) if its time to meeting an obstacle is less than the time set on the setting scale. Or, if the timing mechanism is faulty, detonation will be initiated by the striker point driving sharply forward on impact toward the detonator primer and initiating the detonator.
Oleh Syrota (Georgich©) for the Armed Forces of Ukraine / Entropia.com.ua
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