Drawing on the right ©
Evgeny Kravchenko.

This percussion fuze was used on all early F1 fragmentation , and also used on several other grenades.
The fuze body was made of brass and contained a percussion fuze with striker under spring-pressure.
Two small steel balls kept the striker away from the primer.
Upon release, the safety lever (with fuze cover) was pushed upwarts under spring pressure.
The freed steel balls were pushed out by the striker which was forced downwarts.
This would initiate the primer-timefuse-detonator, which was fitted to the fuze body as a unit.

Photo below © Dr. Ruby.

The photos below show a type that, after throwing, does not lose its cap and spoon.
After being driven upwarts to release the balls, the cap stays on.

Can anyone provide information why this is, and in what period this was manufactured?

Photos Tomek :