Can I use LGA775 heatsink on LGA1156 CPU?

Will cooler that is designed to LGA775 CPUs install on LGA1156 CPU or are they mechanically incompatible?

I'm building my first 1U server and surprise-surprise - Intel stock cooler doesn't fit (unless I'm willing to keep the case open). Places that I prefer to buy stuff from are currently out of stock on 1U 1156 heatsinks so I'm wondering if LGA775 would do the trick.

Solution 1:

The LGA1156 holes are different than the LGA775. So, an adapter bracket would be required for a heatsink to fit both. There are heatsinks which are designed for LGA1156 and LGA775, but unless the heatsink you are planning to get is listed as supporting LGA1156 as well, stay away from it to avoid potential thermal issues in the future.