The M21 is a circular United States
anti-tank landmine
An anti-tank mine (abbreviated to "AT mine") is a type of land mine designed to damage or destroy vehicles including tanks and armored fighting vehicles.
Compared to anti-personnel mines, anti-tank mines typically have a much larger explosive ch ...
that uses a
Misznay Schardin effect warhead. The mine uses an M607 pressure fuse, which can be adapted as a tilt rod fuze. The mine is triggered either by pressure, or by the tilt rod being forced beyond 20 degrees from the vertical by a force of more than 1.7 kg, either of these actions results in pressure being transferred via a bearing cap to a
Belleville spring
A Belleville washer, also known as a coned-disc spring, conical spring washer, disc spring, Belleville spring or cupped spring washer, is a conical shell which can be loaded along its axis either statically or dynamically. A Belleville washer is ...
, which inverts, driving the firing pin into the M46 detonator. The M46 charge first ignites a black powder charge, which blows off the mine's cover, and clears any earth or debris that may have been on top of the mine. A fraction of a second later the main warhead detonates, driving and compressing a steel plate upwards, with enough force to penetrate 76 mm of armour at a distance of 530 mm. Approximately 200,000 M21 mines were produced in the U.S. and licensed copies, the K441 and K442, were produced in South Korea.
Specifications
* Diameter: 229 mm
* Height: 206 mm
* Height with tilt rod: 813 mm
* Weight: 7.83 kg
* Explosive content: 4.9 kg of
Composition H6
__NOTOC__
Composition H6 is a castable military explosive mixture composed of the following percentages by weight:
* 44.0% RDX
* 29.5% TNT
* 21.0% powdered aluminium
* 5.0% paraffin wax as a phlegmatizing agent.
* 0.5% calcium chloride
H6 is ...
* Operating pressure:
** pressure: 132 kg
** tilt: 1.7 kg
References
* ''Jane's Mines and Mine Clearance 2005-2006''
*
Anti-tank mines
Land mines of the United States
{{Landmine-stub