There's no moving parts. The bolt is hollow with a pin projecting from the tip of the bolt back to the head. When put under tension, the outside of the Bolt st

There's no moving parts. The bolt is hollow with a pin projecting from the tip of the bolt back to the head. When put under tension, the outside of the Bolt stretches, but the inside pin doesn't. It's not as strong as a solid bolt of the same size and material. But that's something you engineer around.