Many respondents noted that, so long as they knit at a tight enough gauge, their handknit socks were quite sturdy. While knitters often agonize over choosing the perfect sock yarn, it’s truly only part of the equation. Here’s the thing: the more stitches per inch you have in your sock, the denser the sock material will be. The denser the material, the more likely you are to have a pair of durable socks.
You don’t want to choose a soft yarn. You want to choose a sock yarn with a sturdy fiber and construction. Yarn with multiple plies and a tighter twist will hold up better under regular use. The other question you’ll be faced with is whether to use a superwash wool (this is most commonly a superwash merino wool, though other varieties are sometimes available) or a non-superwash wool. Ultimately, I don’t think either of these options has a significant advantage over the other when it comes to durability.
Handknit socks often require a little more care than store-bought socks. If you wash your socks in water that’s too hot, you will damage the fibers. If you throw your non-superwash wool socks into the washer and dryer, they will not be usable. I hand wash mine in the sink, just to be safe. Others machine wash on a gentle cycle, sometimes with a mesh bag to protect the socks a little more.
When I asked knitters about the durability of their handknit socks are, I got a few cheeky responses to the effect of, “They last forever if I knit them faster than I can wear them!” But there’s something to this. If you only have one of something, and you wear it all the time, it will wear out more quickly than if you can rotate it with a few similar things.
Ask an avid sock knitter, and nine times out of ten, they’ll tell you they prefer to knit with wool or a wool-nylon blend. Not all wools are the same, though, and it’s important to look for wools that are more durable. Sheep breeds with a longer staple length, like Bluefaced Leicester and Romney, are popular for sock knitting.
Some sock knitting methods create socks that are easier to mend than others, while others are more durable from the jump. For example, a slip stitch heel gives you a reinforced heel at the spot where many people are most likely to wear holes in their socks. Forethought or afterthought heels are great for mending. This heel construction can be easily removed when it sprouts a hole, and then you can just knit a new heel in the exact same spot.