The M1, M1A1 and M4 are circular steel cased United States anti-tank blast mines with a distinctive cross shaped pressure spider. The mine was used during the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

and a copy produced in Argentina was used during the Falklands War. Another copy is produced in China. designated the No. 4 mine. Variants of the mine have also been deployed in Chad and

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. Downward pressure on the spider presses down on the head of the fuze, breaks a shear pin, and inverts 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 ...

, flipping the striker downwards into a stab sensitive detonator, triggering the mine. The M4 version of the mine has two secondary fuze wells so that

anti-handling device An anti-handling device is an attachment to or an integral part of a landmine or other munition such as some fuze types found in general-purpose air-dropped bombs, cluster bombs and sea mines. It is designed to prevent tampering or disabling, ...

s can be fitted.

Variants

* M1 – the mine has two filler plugs on the top surface. * M1A1 – the mine has a single filler plug on the top surface. * M4 – as the M1A1 but with two secondary fuze wells, one on the side and one in the bottom.

Specifications

*Weight: 4.80 kg *Explosive content: 2.70 kg of

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*Height: 102 mm *Diameter: 203 mm *Operating pressure: 120 kg to 250 kg

References

Anti-tank mines World War II infantry weapons of the United States Military equipment introduced from 1940 to 1944 {{Landmine-stub