United States hand grenades

The military of the United States has used many of different types of hand grenades since its foundation. Presented on this page is a basic overview.

More commonly known as the Pineapple, the Mk II series (also written Mk 2) was the most common US fragmentation grenade of the Second World War. The Mk II had a grooved exterior originally intended to aid fragmentation of the grenade. However, later studies showed that this design has no effect on fragmentation, though it does provide a non-slip surface that improves grip. The filling was either EC blank fire powder (approx. 0.75 oz or 21 g smokeless small arms powder) or flaked TNT (approx. 2 oz or 57 g); TNT became the common filler from 1942 onwards.

The Mk II was also available in a little-known HE-Blast (better known as concussion) variant and a combined effect HE-Frag variant. This was largely superseded by the Mk III series. The Mk IIA1 (also written Mk 2A1) used the M10A2 or M10A3 fuzes, upgrades to the previous M10A1 fuze used in the Mk II. Later reissued Mk II variants featured the modern M204 series fuze.

Unlike the Mk II, the Mk III (also written Mk 3) was a cylindrical grenade designed to be used as an offensive weapon for clearing rooms, trenches, and other enclosed spaces (i.e., at close range). A concussion grenade, the Mk III series was designed to incapacitate through the pressure and impulse produced by the explosion. The MkIII had a far larger TNT filling than the Mk II series; up to 8 oz (230 g) of TNT, in comparison to 1.8 oz (51 g). Although a minimum-fragmentation grenade, large fragments (most likely the fuze assembly, or surrounding material) could be projected as far as 200 m (660 ft) from the detonation point. The differences between the Mk III, the Mk IIIA1 (also written Mk 3A1) and the Mk IIIA2 (also written Mk 3A2) were improved versions of the M6 fuze: the Mk III featured the M6/A1, the Mk IIIA1 the M6A2, and the Mk IIIA2, the M6A3. Later reissued Mk III variants featured the modern M206 series fuze.

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