Mark 6 nuclear bomb

Seven variants and versions were produced, with a total production run of all models of 1100 bombs.

The basic Mark 6 design was 61 inches (150 cm) in diameter and 128 inches (330 cm) long, the same basic dimensions as the Mark 4.

The Mark 18 nuclear bomb was a follow-on to the Mark 6 and Mark 13, utilizing a fissile pit assembly with around 60 kilograms of HEU and delivering a yield of 500 kilotons, the largest pure-fission (non-thermonuclear) bomb design ever developed by the US.

Mark 18 bombs were eventually recycled into Mark 6 Mod 6 bombs after thermonuclear weapons were deployed in quantity.

The Mark 18 was tested once in Operation Ivy King.