DIYaudio is a better place in general for these sorts of questions. Lots of regular builders there.
Crimp connectors are usually color coded for the speaker wire size, and then you have both metric and English sized tabs. The red crimp connectors are 22 to 18 gauge. The 5.2mm sounds like it’s really an English 1/4" (6.35mm) which will give you just a little over 1mm of play. I would consider upgrading the wiring to 14 gauge stranded though, but it’s not really necessary. In that case you want the blue, not the red.
Sounds like you want a red 1/4": https://amzn.to/3GYVhcW
