I've never tightened one before last week, I used some loctite and put it all together. Had to pull it out the other day to install the multigov and it had held pretty good. I bottomed it out and then used a wrag on the fan and twisted it pretty good. After it sets up for a day and the loctite hardens I don't think it should come loose in normal operation.

(for me, I would rather have to retighten it than damage it by overtightening, I wasn't confident in it being tight enough untill I went to install the multigov).