This M5 x 0.8 mm tap is made by Europa Tools (list price: £15.53). It is designed especially for aluminium alloys. It is made of cobalt high-speed steel (HSS-E), which is much more resilient than the brittle carbon steel normally used for inexpensive hand taps. It can be broken, but it's more frogiving than the usual taps. It has wide flutes for easy chip removal.
Please note that the images show a slightly different tap from the same manufacturer, that we sold before this one. This one has a blue ring and slightly wider flutes than the one pictured. We'll update the images soon.
Below is a video/tutorial Harry made on tapping MakerSlide.