Help! cant make object a solid, already used solid inspector

Hello, for some reason i cant make a wrench i have a solid… I already tried using solid inspector and it says everything is good but when i make it a group it does not take it as a solid… i dont know what im missing, could you help me out sketchup community?

Upload the .skp file so we can see what you’ve got.

wrench.skp (6.1 MB)

Hello, attaching the file

You have created your model with too many segments in circles and arcs. Even scaled up, as you have it (the ring spanner is 23" diam approx) SU is suffering from ‘small edges’ issues - edges created that are too short so that their endpoints get merged, and fail to create faces.

Turning hidden lines on shows just how many edges there are in the model, some of them too small.

Draw the wrench again with many fewer segments in your arcs or curves. I don’t think this one is easily fixable, though you might try again with it scaled up by another factor of ten or even a hundred.

Hello John, thank you very much for your knowledgeable reply. I will try to edit it so it has fewer segments.