The Bolt Puzzle





Introduction: The Bolt Puzzle

This instructable will show you how to make a great pocket sized puzzle. Great for a gift.
P.s. This was not my idea credit goes to This Site . However the pictures are my own.

Step 1: Materials and Tools

To make the Bolt puzzle you will need:

A left-handed bolt (For size, look at the picture) and matching nut.
(By the way you can also use a right-handed bolt if you don't have any left-handed bolts, I have used a right-handed bolt and not had any one guess it thus far. However the puzzle will no doubt work better with a left-handed bolt.)
A split washer (Notice that I split it more, see picture).

A file for metal.
A saw for metal.
A welder.
A vise.

Drill with wire brush attachment.

Step 2: Step 1

Now take your bolt and put it in the vise. Then file out a v-shaped notch on two of the bolts sides(See picture 2).
Note: These notches do nothing, But most people will think they are the key to solving the puzzle.

Step 3: Step 2

That done cut off a piece of the bolt, about a quarter of an inch of the end of the bolt. (See picture for help).

Step 4: Step 3

Now screw the small piece of the bolt about a quarter of the way into the nut (see picture). Make sure you don't screw to far in otherwise the other piece of the bolt will not fit in nicely. Next weld them together just like in the picture.

After welding you will notice that there is a fair bit of heat discoloration on the the metal. So using the wire brush attachment on your drill buff the bolt so it is nice and shiny or you can use aluminium spray paint.

For those who don't have a welder here is some great ideas:

If you don't have a welder you can use a blowtorch (or something similar to heat up the nut and piece cut from the bolt) and some solder.
(Thanks kasssa)

Or You could also use a dab of JB Weld to secure the nut and piece of bolt.
(Thanks CimarronWarrior) 

Step 5: Step 4

Now all you have to do is put it together. Look at the picture for help.
Great, you're done, Now all you to do is choose your "victim" and ask him to remove the washer without bending it. He will most likely struggle with it for about 5/10 minutes before giving up. Make sure you keep telling them that it is possible and is pretty simple, otherwise they give up sooner. When he gives up put it behind you back and remove the washer. Then put it back together without the washer. Give this back to him and if he still can't guess, go ahead and show him. He deserves it for the time you wasted.

Wiggly bolt<>Sometimes the bolt doesn't screw tightly into the nut. So it gives the trick away,so what you can do is give the end of the bolt that's going into the nut(The nut that is welded to the small piece of bolt) a couple taps with a hammer this makes it harder for the bolt to be unscrewed. Careful to much and you'll need a pair of pliers to unscrew it, which kind of ruins the puzzle.
P.s. If you see any problems post a comment about so I can fix them.



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You should make one that can't be opened at all, and one that can. Alternate between giving the dud one out and solving the real one , would it drive everyone crazy ? :o

1 reply

Good idea!

I was skeptical that anyone would fall for this but I had to find out.

I made it with slots that go right over and through the head and a washer that almost makes it possible ( the leading upper edge of the washer and the angle of the slots make the person actually tighten the bolt as they try to get the washer off).

Anyhoo, the results are as follows:

1- 11 Year old girl; solved in 5 minutes.
2- Woman with no real mechanical background; solved in 2 minutes.
3- Male mechanic; gave up after 30 minutes.
4- Another male mechanic; gave up after 20 minutes.

It is very funny watching the disgust they have with themselves as they are told the solution.

1 reply

Yeah this puzzle is great because to most it is illogical. They look at it and see a bolt welded to a nut, "obviously" the nut will not come off. A mechanic is going to see the weld and imediately assume the nut ain't going nowhere. Whereas someone with less knowledge will try anything.

DIABOLICAL !!!!! I LOVE it ! I've seen this 'ible a few times and never read it - VERY Glad I read it today, though ! :) Thanks for the entertainment, I cannot wait to try this one out of my Mom and Dad ! Wooo-hooo ! ESPECIALLY my arrogant, "holier-than-thou" Brother ! Muahahahahahaha ! Thank you VERY much - 5 out of 5 !

this was a funny project. I had funny building it and fun watching people try and solve it. it made for a great stocking stuffer too.

I like this a lot .... I'm making one today.... the notches are very good touch.

1 reply

Yeah they distract the person doing it. When they look at it they see the notches and immediatly think it is part of the puzzle.

Really cool! I finally have an excuse to buy that welder I've been wanting for years. Nobody would figure this out, unless by accident.

I would really like to make one of these, but I cannot for the life of me find a left handed bolt. Where is everyone getting theirs?

1 reply

I have a local bolt supply house. Can get just about any fastener known to man there!!

Nice brain candy...I wonder if Loc-Tight woud work? I was also going to say that you could get a Uni-Strut nut (1") in length, and Loc-Tight to hold the end welded piece, with out having to use a welder. The suggestion of GB weld is a good one.

1 reply

Unfortunately the trick really needs the weld showing to convince the contestant that the nut won't unscrew.

one drop of superglue will do the trick if you dont have a welder

1 reply

It is the weld that convinces the folks it cant unscrew though.

What stops a guy from simply twisting the bolt during his attempt to take the washer off? I know the first thing I would do is try to take off the nut, and during that process, what is going to stop me from then accidentally unscrewing it? Especially since you state it's possible for the original person to just twist it off behind their back.

This seems like a game that only works on people with an IQ under 70. So I would find a way to not have the "prey" be able to open it, and WAY MORE important than that is... you MUST have UNIFORM color on the bolt!! Anyone with an IQ over mentally disabled, will wonder why there are two colors. (And if they think far enough that the WELD discolored it, then why would the other side not also be discolored. I think the JB weld would work the best, since it can be hidden better, and won't discolor the bolt sections)

4 replies

Actually as mentioned above, the guys with the most knowledge will likely 'know' the nut can't be unscrewed. Also not he specifies a left handed bolt which most folks will instinctively try to unscrew it right handed which tightens the left handed one. I am going to try it.

Never learned about heat transfer did you? The other side could easily not be discolored because the bolt absorbed enough heat to keep the other side cool.

If you tighten the nut so that it is not easily removed (but not enough that you can't undo it) then it'll be fine. the weld also keeps people from trying to remove it (looks like its stuck), JB weld would not have as good as an effect.

it looks better when both sides have been looks uniform and clean

The point is that they see the weld so they wont even try to unscrew it because is WELDED. Your idea of using JB weld is a good idea (not), you should do it and then you can use it on people with an IQ of under 40 that also think is a good idea.