80mm case fan works for cpu fan?

I am looking to upgrade some fans in my case to keep everything inside nice and cool. I picked out a fancy case fan I am happy with, now I most likely won't be overclocking my CPU just because I know so little about it, but I figured I could at least upgrade the fan that is on top of my CPU's heatsink just so then it can be cooled a little bit more.

The fan on top of my heatsink is 80mm, this is most likely a no brainer and I'm pretty sure it will work I just want to get a clarification and final go, so I'm wondering if I can just buy a 80mm fan and replace the one thats on my CPU? *The reason I'm wondering is because on Newegg it saying these are case fans, but it's just an 80mm fan so I'm figuring regardless it'll work out fine I think the only thing I need to worry about is the depth of the fan, if it's too deep then I'd need to get like long bolts.

Something like this one here to go on top of my CPU heatsink.

I just need someone to say yeah its cool, I feel dumb making this thread =p

Thanks for your time.