Ever wondered why there isn't an Allen key (or hex key, if you prefer) equivalent to the adjustable wrench or spanner? Turns out it's actually quite a complex engineering challenge. But this is 2025, ...

“Everyone should have a set like this on hand.” ...

You could amass an irregular collection of Allen wrenches by saving the ones that come with build-it-yourself furniture, but the way to actually have every hex key you need on hand is to get a nice, ...

An awful lot of engineering for such a small tool. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.