This unknown grenade was found by croatian soldiers during croatian military operation "Flash" in 1995 for the liberation of the occupied part of Croatia, called Western Slavonia.
The grenade was found in Serbian house after liberation.There was large quantity of this type of the grenades in that house but it is unknown who manufactured these.
The grenade is typical war-made, made of steel pipe, brazed on its ends and processed on lathe and on horizontal milling machine for better fragmentation. On the upper side it has a threaded hole 14 mm in diameter which holds a threaded adapter. This adapter has a drilled hole in the middle of 5,5mm in diameter, through which the pyrotechnical slow-burning fuze is set.
This fuze has detonator No. 8 crimped on its end.
The grenade was painted in gloss black colour. The fuze was waterproofed with wax

Total length(without fuze) : 140 mm
Diameter : 40 mm
Weight : unknown
Explosive filling : 180 grams of Vitezit
Fuze delay : 2-3 seconds

Photos © Goran.

The grenade shown above has been repainted and was inerted through the base.
The hole in the bottom is not standard.