Consider the W48 warhead, the entirety of which (not just the core, but the whole thing) was 6.1 inches in diameter and less than 60kg. Or the W54 was reputedl

Consider the W48 warhead, the entirety of which (not just the core, but the whole thing) was 6.1 inches in diameter and less than 60kg. Or the W54 was reputedly much lighter, but with a larger diameter.