type 93 japanese mine

[kiwieod]

got this relic japanese mine,probably came from the pacific islands.it seems to be made from copper sheet metal which seems unusual as copper would be required for more important things and in short supply(maybe not in japan)
anyone know why?

 

[US-Subs]

It may have had something to do with reactivity to the explosives. If I recall correctly it had a fill of picric acid, which has a tendency to form sensitive explosive salts when in contact with some metals. The Japanese used it in some bulk applications for ordnance; typically bombs, warheads, torpedos and mines.

 

[microplastic]

Could it be brass? Copper would be too soft, I think. When brass oxidizes, a copper layer forms.

 

[Eggburt1969]

Details on the Type 93 anti-tank (AT) mine, from the British 1945 publication 'Japanese Ammunition Leaflets - Section F - Mines & Booby Traps', are below.

Most of the body was mild steel, tin-plated (presumed) steel, other parts copper or copper alloy.

As US-Subs mentioned, the use of picric acid (trinitrophenol) as the main and booster charges likely necessitated the use of copper/copper alloys and tinned steel.