I purchased a pair of these socks for $16 in Manchester Center, Vermont in 2007 and used them for the last several hundred miles of that hike to Katahdin. Then they lasted the whole
2,670 miles of my 2012 PCT hike, where they developed a couple small holes around the heels.
Darn Tough boasts a lifetime guarantee, so I went to their web site, and sent them to the owner’s address ( I did wash them twice).
Two weeks later, I received a UPS box with this EXACT duplicate ( color, model, and size) pair of socks.
I’m saving them for my upcoming attempt at thru hiking the 3,000 mile Continental Divide Trail.
I’ve tried numerous brands of these merino wool type socks and Darn Tough have made it to the top of the list.
Tom Jamrog's Weblog 
Damn right! I used two pairs of Darn Toughs on the PCT, and got a few tiny holes in the ankles. I switched to Smartwools around Lake Tahoe for about a month, and all three pairs of Smartwool socks I got were destroyed before I got out of California. Went back to the same two pairs of Darn Toughs I’d started with.
I’ve found one of the best things to do with some of the thicker DT socks is to turn them inside out before washing, and make sure to rinse them a few times before putting them into the washing machine. That gets them nice and soft for the next day or two of hiking.
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