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, ...

The Allen key turns 115 this year. It’s strange to believe that in all that time, no one has come up with an adjustable version, but apparently true. Luckily [Chronova Engineering] has taken up the ...