QUESTION: Just, why ?

I was exploring a local swap meet and found this. For the life of me I cannot figure out why one would need an adjustable spanner at each end.

I mean it's ADJUSTABLE and having two on the same handle means you can't tighten a nut and bolt at the same time.

enter image description here

enter image description here

  • 2
    See garagejournal.com/forum/threads/… for more info. Made for many years, since the 1910’s and stopped sometime in the 60’s apparently.
    – Jon Custer
    Commented Sep 27, 2023 at 2:07
  • 3
    @Criggie, I've seen some of my dad's tools that look like that, yet were store bought. Not everything was chromium plated back then, and older steel tools tended to pit like that in wet climates or when used in wet applications. The knurling on the adjustment is plenty distinct, which wouldn't necessarily be the case in sand casting. And if it was cast as a single piece, the jaws wouldn't have the seam between them and the slide body as it does. Check out my answer below for more info, if you're interested. Commented Sep 27, 2023 at 21:13
  • 3
    Maybe if you're lucky, everyone else who sees it will wonder the same thing until the next swap meet :D Commented Sep 28, 2023 at 3:46
  • 8
    One end is metric, the other end is standard. Commented Sep 28, 2023 at 16:55
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    Whoever deleted Harper's comment: BOOOOOOO. fheckin lock the comments then.
    – Mazura
    Commented Sep 29, 2023 at 3:06

6 Answers 6


According to the thread on the Garage Journal web site, these type of wrenches featured 2 different Jaw sizes and were also thinner than normal so as to be more easily used in tight spaces.

This is the ad for the version made by Crestoloy (a different ad shows a model made by Diamond.) enter image description here


Additional information specifically on the Crescent brand is available here: https://aplanelife.us/blogs/f/a-mystery-with-two-ends


I used to have one of those (Crescent brand). The jaws at either end had significantly different capacities. One tool instead of two. As someone who frequently had to lug a heavy tool bucket around, makes perfect sense to me.

  • 10
    What does "significant" actually mean here? The big one can be adjusted to the smaller one's sizes, so the only times I can think of that this doesn't work are due to working space limitation, but at that point, I wouldn't even be using an adjustable wrench in a tight space to begin with because there are better tools for that.
    – Nelson
    Commented Sep 27, 2023 at 3:55
  • 2
    @Nelson No, they are not the same, even if set to the same width - try it and see. The whole point of these adjustable wrenches is to avoid having to carry around complete sets of single-size tools, which admittedly are superior for some purposes. But Good Enough is exactly that.
    – kreemoweet
    Commented Sep 27, 2023 at 21:29
  • 2
    I'd still carry my tiny one, the big one that can go over 1/2 NPT unions, and that thing to back up either one, instead of the middle sized one I leave in the truck for that. Want....
    – Mazura
    Commented Sep 28, 2023 at 1:03
  • @Mazura I think that could actually be its use case - as the 2nd (holding still) spanner for but big fittings and smaller ones in tight spaces. IMO it would be much more useful if the smaller end were smaller still - a lighter build and perhaps thinner jaws for the same opening
    – Chris H
    Commented Sep 28, 2023 at 8:00
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    @kreemoweet: you're the one posting an answer for the benefit of other people that are curious. It would be better if you could put into words what some of the differences are, since not everyone will even have multiple adjustable wrenches they could go grab, and reading two sentences to guide their thinking in the right direction would still be faster. (This is on HNQ now, so the audience includes people who don't use wrenches regularly.) This is what Nelson was trying to encourage. Commented Sep 29, 2023 at 1:13

If you are working on something with a LOT of fasteners, of two different sizes, you wouldn't want to be continuously adjusting a single wrench back and forth. This lets you have both settings available.

Or, if you were going to carry both wrench sizes in your toolkit anyway (to have the full size range but also fit in tighter spaces), this might be a cheaper (and lighter weight?) alternative.

Or it may just have been "You can't decide? Have we got a tool for you..."

But I agree it doesn't look especially practical, and unless there was a very specific market (preassembled toolkits? military procurement?) I'd be surprised if it did well in the market.

I'd suggest trying a image search on the web and see if there's a write-up somewhere. Tried a quick search myself and did find hits but haven't dug into whether any of them have the history.

  • 3
    I've used plenty of adjustable wrenches, Crescent brand and others, and even for the same size bolt/net (even the same exact bolt/nut), continuously adjusting the wrench is necessary to slide on and fit correctly, as well as just to stay on. Personally, I only use these types of wrenches as a last resort, or if I forget just how lousy they work and end up having to get the correct socket or combination wrench after damaging the faster and/or my knuckles. ;-) Commented Sep 27, 2023 at 21:35
  • 2
    There's a technique to sliding a thumb to tighten them as you put them in place... I find that good adjustable wrenches work well enough for many tasks, and weigh a lot less than a full inch-plus-metric kit. Compromises, as always. (Then again I've never been a motorhead, so I don't have a rolling cart full o' tools.)
    – keshlam
    Commented Sep 28, 2023 at 4:13
  • I know the thumb technique well, yet the way the wrench slides never really makes for smooth operation. The backlash always seems to lockup the screw. Maybe mine are just old and/or cheap, but they just don't stay adjusted. I have to keep my thumb on the screw, which limits my grip and power. I wish I had rolling carts for my tools, then I'd only need 2 of the massive ones, instead of dozens of small toolboxes with dozens more bags and just plain loose power tools. Lol. I have way too many tools... Commented Sep 28, 2023 at 16:54
  • Same answer in my words: You can set one end to one size and the other end to another size and then easily switch back and forth between those two sizes without having to make an adjustment to either worm screw. Useful if your work has nuts of two different sizes.
    – Wyck
    Commented Sep 29, 2023 at 19:42

The point is the same as the point of owning 2 differently sized Crescent wrenches.

You can choose to only own one large wrench and use it for smaller fasteners, but some people will prefer to have choices. This tool seems silly to me, but I understand why someone might want one.

  • I think this hits on the point. If you are going to own multiple sized crescent wrenches why not have the ability to purchase two in a single tool instead of having to buy multiple ones.
    – Joe W
    Commented Sep 27, 2023 at 16:38
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    @JoeW - well, with two different ones you can hold both the bolt and the nut...
    – Jon Custer
    Commented Sep 27, 2023 at 18:39
  • @JonCuster But you wouldn't really need two different sizes for that.
    – Joe W
    Commented Sep 27, 2023 at 19:00
  • 1
    @JoeW - true, but I don't have two of one size either. The point is that sometimes you need two wrenches, so that double-wrench won't do you any good if it is the only one.
    – Jon Custer
    Commented Sep 27, 2023 at 19:06
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    The point is that you usually need two, no matter what. This is the third one that keeps you from having to carry four (two big, two little) instead of a singular mid sized one that isn't "good enough" half the time and leads to either it's schlock or I'm going shopping.
    – Mazura
    Commented Sep 28, 2023 at 1:11

If you look closely, you'll see in the 2nd picture on the left size, it says "8-10 in", meaning it has the wrench ends of an 8" wrench and a 10" wrench. This means that one side is slightly larger than the other.

Here's an eBay listing that has slightly better pictures of what I think is the same model of wrench.


To me, the slight difference in the head size without the added length of a 10" wrench doesn't make the tool that much more useful than if they simply had the 10" head with a shorter handle.

However, a dual headed adjustable wrench seems to be somewhat common(?) for older tool sets, as I found a variety of different versions.





And a forum talking about different varieties, as well as what they are and why they were made/used.


I'm just guessing here, but this may have made more sense when steel and/or tools were relatively more expensive than they are today. There's also a semi-common modern desire to "own all the things/tools", while older generations bought only what they needed, and only if something couldn't be repurposed or wrangled into working.

Also, some work pants used to have a long, thin pocket or denim loop that could basically store exactly one wrench down the side of the leg (before cargo pants/shorts). Overalls and coveralls also tend to have these pockets and loops. If you had to choose what wrench you wanted to put in the pocket or loop, the double headed wrench might fit the need. Growing up on the farm, we often kept a hammer in the loop, but not everything is a nail.

I found a modern version that has both the loop and the pocket (2 pockets in this case).


  • 1
    a double headed wrench wouldn't easily fit through the loop.
    – Jasen
    Commented Sep 28, 2023 at 1:03
  • 1
    Not everything is a nail, but with this wrench in your hammer hanger, you don't need a hammer! ;)
    – FreeMan
    Commented Sep 28, 2023 at 12:07
  • 10" or even 8" seems like a heck of a jaw opening to me. Not many nuts that size - and if there were, they'd need a darn sight longer handle on the tool.
    – Tim
    Commented Sep 30, 2023 at 12:42
  • @Tim, the 8" and 10" are referencing the length of the tool, not the size of the jaws, so it's an unfortunate misnomer. The actual size of the jaw openings vary from brand to brand, but 8" models are usually 1-1/8"-1-1/4" wide max and 10" models are around 1-1/4" to 1-1/2" wide max, from what I can find in online descriptions. This is why a tool with both an 8" and 10" adjustable head doesn't make much sense, since their max capacities are so similar. The 8" head is slightly slimmer to fit into narrower places, but again, that's not much difference. Commented Oct 2, 2023 at 18:25

I wanted to share my thoughts on this, which may or may not be right.

In addition to what the others have given, I see 2-3 benefits:

  1. the 2 ends may be suitable to right-handed & left-handed users & situations: giving the better grip in one orientation for one group of users & one set of situations. [ In case it is not obvious to the downvoter(s) , the 2 heads are not rotational-symmetric , they are mirror-symmetric , which might make the tool suitable to either hand & either orientation ]
  2. when the threading/alignment/tightness goes bad on one end, the whole tool need not be discarded, because the other end might still be good, which improves the lifetime of the tool.
  3. unintentional benefit: the thicker end gives a better control/handle/grip when holding at maximum distance.

This is just my guess-work.

  • 1
    If you read the answer above that includes the advert then you can improve your guesswork.
    – Solar Mike
    Commented Sep 28, 2023 at 13:15

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