How to Remove an Oversized Allen Bolt...anywhere!





Introduction: How to Remove an Oversized Allen Bolt...anywhere!

If you've ever been like me, looking at what appears to be the biggest Allen Bolt ever made while realizing the largest wrench in your tool kit is only good enough to fix a pair of sunglasses, you might think you're a tad bit hosed.

Never fear! Here's a quick and dirty solution.

Step 1: Get a Bolt and 2 Nuts

The trick is to either buy, or dig through your piles of bits and pieces, and get a bolt whose head is either the same size as your Allen bolt, or slightly larger, and 2 corresponding nuts.

* If you're dealing with a car or motorcycle, there's a pretty good chance you'll find one of these suckers holding useless things together, like shocks or fuel pumps.

Now that you have your bolt, make sure it fits. If you've got an oversized one, just file or grind it down to fit.

Step 2: Assemble Your Tool

This is the easy part. Thread the 2 nuts onto your bolt and back them against each other hard! For those of you scratching your head, that means turn them in opposite directions in relation to each other. They will tighten up very solidly.

If you're planning on using a 12-point socket or box-end wrench, make sure the points will line up with the splines in your wrench.

For 6-point sockets/wrenches, or for those of you using anything open-ended, make sure the nut faces are parallel to each other.

Step 3: Remove Your Allen Bolt!

Put the newly assembled tool into the Allen Bolt and start turning! To prevent the top nut from just spinning off, make sure you turn the bottom (closer to the Allen) nut to remove - turn the top (furthest away from the Allen) to tighten.


Now, throw that little sucker into your tool kit with've made your own tool from basically nothing!

James Irmiger
Lead DC - Facilities Manager
TechShop SOMA



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    35 Discussions

    Am I the only one who's now headed off to the hardware store to buy a full set of rod coupling nuts for this use? I can't justify a full set of giant hex bit sockets for my ratchet, but a handful of coupling nuts seems downright sensible!

    I needed a 14mm Allen wrench and bought a 9/16, then turned it down on the CNC. Some times you kick yourself thinking, "I didn't I think of something so simple?!" This is a great idea. I hope I remember it next time... Thanks!

    Brilliant, so simple, yet so smart. Thanks great tip

    Ah, this could come in handy. LOL at. "useless things like shocks or fuel pumps"

    Great Idea!
    The only problem is that these big screws are often glued an very well tight.
    Last time I tried to open one of these(inside a hydraulic motor, so, not rusty and lubrificated) It broke not only the screw as the real allen key itself, so, only works sometimes.

    An old trick, but old tricks are worth repeating, because new DIY persons at coming on the scene all the time. With a welder available use short bolt with all threads spin on a single nut weld the nut to the bolt. Or drill a hole near the end of a length of strap metal stick the bolt through weld the bolt that comes through the strap to the strap. Pretty it up put it the tool box for the next time. When I worked in the oil field I carried many specialized shop built tools on the truck

    Bravo pour l'astuce ! Il suffisait d'y penser en effet.

    We should post instructables about basics or tricks like this more often, sometimes they can be very very useful.

    2 replies

    as times get tough, we need to get back to some old ways of doing things.
    -like snoop said, Every penny counts.

    Another cheap option is to buy a coupler in the size of the allen head, and put a socket on the other end. I've been in a situation (removing a Suzuki wheel axle) where the bolts + 2 locking nuts trick wouldn't work and it took all day to figure out that I could buy a $3 part at the hardware store and have it handled in seconds.

    The right size allen wrench is always the best option, but they're often expensive and special order. In a pinch the coupler works great.

    " If you're dealing with a car or motorcycle, there's a pretty good chance you'll find one of these suckers holding useless things together, like shocks or fuel pumps."

    You big meanie... whiskey came out my nose when I read this one...

    Nice way to solve the problem. Twin nuts do a lot of tricks like this one.
    But in this case take extreme care: Cheap bolts and nuts are made with different steel as a proper big Allen key, and you can damage yourself or the piece you're working on if it breaks as you force it.
    Nice anyway!

    Excellent idea my friend, thank you for sharing this. I will be putting this to good use.