[Damo] has an interesting LED bulb project with a neat twist: he converted some outdoor lighting to 12 V LED lighting with some self-designed bulb replacements and decided to reuse the existing GU10 sockets and wiring. That meant putting GU10 lugs onto his custom PCBs, but he ran into a snag.

Those distinctive lugs that twist into GU10 sockets? [Damo] simply couldn’t find anywhere offering to sell them in small quantities. So he did what any enterprising hacker would do and found a substitute that was both accessible and economical: M3 bolts. Apparently, socket-headed M3 bolts are pretty much identical in size to GU10 lugs. Who’d have thought?

[Damo]’s retrofit worked great, and thanks to M3 bolts he was able to re-use the existing weatherproof wiring and sockets in his yard. His design files are here on GitHub.

We do love using things for other than their intended purpose, but as [Damo] points out, GU10 sockets are normally connected to mains power. So if you decide to use his design (or use GU10 sockets for your own purposes), be aware that you’ll have hardware that looks interchangeable with other (mains-connected) sockets, but isn’t. Be mindful of that, and take appropriate precautions. Avoiding electrical oopsies is always worth putting effort into, after all.