As I've said in previous topic I'm playing solo on server to avoid sleeping and invite friends from time to time.
Me and my friend we're playing together and restarted couple of times surviving like 10-15 in-game days in average. I would say we started over again somewhere near 10 times and we haven't been able to find sledgehammer not a single time so it became a meme for us. Each time we visited few major places for looting tools like McCoy, The large warehouse in Muldraugh, hardware stores, small warehouses, warehouses out of town and so on. But I'm playing on my save for 1,5 months. This is my first attempt to play more than 15 days. I've visited all of them (I mean, that I've mentioned before near Muldraugh, Rosewood, March Ridge) and and haven't found any sledgehammers too.
Recently I've started a SP game with a debug just for first time and for fun because I've was curious to visit a Louisville and what to expect in it when I would try to reach it on my main world. I've accidentally found the sledgehammer in a random alone crate in military camp near Louisville like instantly. I've become suspicious that isn't just my low luck. Then I've visited a McCoy on same save and disassembled all the crates. I've found 3 sledgehammers just only in McCoy. I've started a few more worlds on MP with same config that I used to play on my main world and with help of debug I've disassembled every single crate on all of the mentioned places including few more hardware stores and warehouses in Louisville. And to my surprise I haven't found any sledgehammers too. I even tried different amount of months since the Apocalypse. Still haven't found any.
• Betterhandwash 41.60+
I have some footage of how I've been disassembling or worlds with all that disassembled stuff, but I've wasted like 40-60 minutes on each world. The sledgehammer in my hands is given trough debug to disassemble crates