PROPbay.com - Nostromo destruction bolts

Two bolts used in the famous sequence where Ripley (Sigourney Weaver) activates destruction of the Nostromo.

The bolt on the right is one of four that were used on screen.
The bolt on the left didn't make it to the screen BUT was used by the supervising sound editor for designing the sound effect heard when the first bolt is screwed into one of the lighted pistons.

The bolts are slightly different from each other. Their bodies are 100% similar but the bottoms and acrylic heads are definitely different in shape (and even texture). This observation leads me to think that a few sets of four bolts were made during production (two sets, maybe three), all slightly different from each other (don't know the reason why... Sir Scott's legendary obsession for details, maybe ?) but just one was used for filming.

The bolts were acquired from two key members of the A L I E N production crew who had kept them in their respective collections since 1979. They both come with a letter of authenticity signed by their former owners and are in excellent condition, considering their age.

NOTE : You don't see that on screen but it's interesting to note that prior to be screwed on their respective lighted pistons (or whatever they called them), the four bolts were locked at the four corners of the destruction box. The 3rd image shows one of the destruction bolts locked in its corner and the 4th shows one of the clamps that was used to lock the bolts in place before they were used.