Japanese Ceramic Grenade

One of my meandering ebay searches turned these up two weeks ago and it arrived today. Fellow in Japan evidently came up with a small stockpile of them and listed them on ebay for $20 with $15 shipping which is way below what everyone else is trying to get for them.

Ceramic grenade produced late war with the intention of issuing them to the general populace for defense against invasion. Thinking about it, I wondered what damage a ceramic grenade would cause. Fragments of porcelain in legs? My suspicion was that the porcelain would just disintegrate and apparently, that's what happened. These were shock grenades similar to a flash/bang and would more likely disorient or disable rather than kill or seriously wound. I think it's pretty neat. They were to be filled with powder and a fuse would be pushed/crushed into the top. No going back when fuse installed I guess.

Customs paperwork states it is pottery which is correct and probably easier to export/import than saying grenade.

https://www.milsurps.com/images/impo.../45YisrQ-1.jpg

https://www.milsurps.com/images/impo.../2yO1Cb5-1.jpg

https://www.milsurps.com/images/impo.../5ChOp8W-1.jpg

https://www.milsurps.com/images/impo.../wPXXSBT-1.jpg

Quote:

---

Originally Posted by Aragorn243

what damage a ceramic grenade would cause.

---

I should think they'd be like a concussion grenade too...for the most part. They look exactly like what was originally termed "Grenade" hundreds of years before...full circle.

Neat find! As I believe my training taught me, the shock wave (vicinity and brisance) was what did damage to tissue, not necessarily the fragments, which is why the pineapple grenades were eventually dropped (no pun intended) for a redesign.

But I wonder if the quality of the explosive, at that envisioned time, would have been up to the brisance required to do damage and not just create noise and smoke. Perhaps a 'feel good' weapon, makes you think you are still fighting when there is no realistic hope left at all.

I found a guy on ebay that makes reproduction fuses and caps for these. They don't work obviously but may give an idea of how they work. But alas, I still can't figure it out. Looks like there is an abrasive on the top of the inner fuse and an abrasive on the external cap. A rubber cap is provided when not being used. So perhaps you take the rubber cap off, put the abrasive external cap on, jamb down and twist and throw it before it blows up. Supposedly, these were used on Luzon, Okinawa and Iwo Jima as well as the home Islands.

Quote:

---

Originally Posted by Aragorn243

there is an abrasive on the top of the inner fuse and an abrasive on the external cap

---

Nice,
Maybe 'Abrasive' like some type of flint?
Just enough to spark and ignite the fuse ?
Makes you wonder how long until the ignition

All just a guess. But will really make a nice display and conversation piece.

Any markings on it ?
That may ID the Kiln it was made at.

From Wiki:

Type 4 grenade - Wikipedia

Design:

The Type 4 grenade had a fragmentation body made of terra cotta or porcelain materials. The grenade was round-shaped with a bottle neck with a rubber cover and a simple fuse. This detonator was no more than a blasting cap crimped on to a five-second length of fuse. The other end of the fuse, which was outside the rubber plug, was covered with a match-head composition. A slip-on rubber cap covered the whole neck, and fuse. A small, loose wooden block with an abrasive composition on one side was contained in the rubber fuse cover.[1]

Also used in Vietnam.

https://www.milsurps.com/images/impo...sdiagram-1.jpg

Above picture from here:

A War to be Won

No markings that I can find other than the distinct ring around the base which many don't have.