How to Make an Emergency Hex Key / Allen Wrench





Introduction: How to Make an Emergency Hex Key / Allen Wrench

If you need an allen wrench in a pinch, you can use this trick to tide you over until you find a real one. I used this to tighten down my bike seat and ride it a few miles home to a real hex set.

Step 1: Materials:

1) A Pencil (hexagonal barrel)
2) A Knife
3) No Hex Key

Step 2: Make

Cut off the end of the pencil. If you press the blade straight down into each face of the pencil (press, turn the pencil, press, etc.), the tip will snap off almost cleanly. If any splinters stick up after the break, flatten them down so the pencil can jam as far as possible into the bolt head.

Shave the sides of the pencil down to size. Keep the peelings parallel to the faces. Make your shavings pretty thin. Test to see if it fits. If it's tight, that's good.

Step 3: Big Emotional Payoff!

Insert your new allen wrench into the bolt head. Turn slowly.

If the wrench slips, it has been stripped (wood is soft), go back to step 2.

If the bolt is satisfactorily tightened, celebrate! Then do what it takes to find a real allen wrench, and get this baby tightened down for real.

It took me three rounds of cut/shave/tighten to make my bike seat rideable.

You can even make your hex wrench back into a pencil when you're done! So much versatility!



    • Science of Cooking

      Science of Cooking
    • Pocket-Sized Contest

      Pocket-Sized Contest
    • Trash to Treasure

      Trash to Treasure

    We have a be nice policy.
    Please be positive and constructive.




    Just don't bring this into any airports star......

    Not flown recently? "OMFG!!! It's a plastic see-through bottle of water!! Take cover!!!!" "And that will be 10p for the plastic bag. No, you can't use your own. You have to buy ours to put yours in."

    I think he was referring to the bomb scare involving star...


    As a user of power tools, I don't think I'd trust the tork one can get with soft wood versus steel. However, a clever use of thought on your part. This is probably fine for "finger tight" hex screws.

    Which is why this is an emergency hex wrench. It's also better than "finger tight" (otherwise, why make the tool?).

    It's certainly better than "finger tight" on a socket cap screw like this, where you can't tighten it with your fingers!

    I actually made an instructable that is more important than I thought when I made it, the "seatpost toolkit". Recently I have considered inconspicious and not-obvious-to-casual-theives places to stash a few allen keys and such, for that time when one's bag falls off on a bump that was just jarring enough that the bag's impact on the road/trail is not noticed. I recently saw, on a rusty beater that looked intentionally neglected for ugliness, a cheap multi-bit screwdriver taped to the toptube. The screwdriver handle was transparent plastic, so the remaining metal bits blended in with the brownish/rust frame. A darn clever idea on a beater, methinks. Also an intersting thing to try: if one can find a small enough set of folding allens, that could be stowed in the seatpost, handlebar, or even barends on flatbars. I suppose even the nose of the saddle could hide a tool or two if it has no plastic strengthener thingy. Imagination is golden...