Bolt Detent...what is it? Most people don't have a clue what a bolt detent system is or what it actually does. In short... a bolt detent system is usually a spring loaded device found inside the door of a safe. The device will not allow the person operating the safe to extend the bolts while the door is open. This is to protect the finish on the safe, especially important if one has an expensive high gloss finish on the safe. If your safe doesn’t have a bolt detent system, then accidentally closing your safe door with the bolts extended can be a painful, costly experience because when the door is closed with the bolts extended the bolts will likely scratch the exterior paint.