The security hierarchy is the difference. A box clasp with safety uses the box mechanism as the primary lock and the catch as secondary, while a double latch clasp treats both locking points as equal.
Stone Story
When Friedrich Mohs published his hardness scale in 1812, corundum, the mineral that produces both sapphire and ruby, landed at 9. That explained something the sapphire trade already knew empirically: corundum holds its polish under daily wear.
Built For Ease
Developed partly in response to the usability requirements of wrist jewelry, where single-hand closure is a practical necessity, the tongue-and-housing mechanism of a box clasp requires less fine motor precision than springring or lobster clasps. This makes it one of the more accessible closure options in fine jewelry production.