This is the sort of wrench I have in mind:

enter image description here

In the Wikipedia article (Socket Wrench) displaying this image, it is described as a spark plug wrench, but there are wrenches of this style in many other sizes, and for many other purposes - anywhere one has no access from the side and a long bolt or stem preventing even deep 'conventional' sockets (having a square socket for a drive on the other end) reaching the nut.

The image itself is labeled "box spanner", but if I search for that at Home Depot, Harbor Freight, etc., I get back the type of wrench that has a closed, 12-point ring on the end of a handle, and if I search for "spark plug wrench", I get tools specifically for that purpose. I suspect that "box spanner" is British usage; is there a term in American usage that picks out just this style of wrench, regardless of its purpose?

Update: Thanks to everyone for your help and advice. As it happens, I was able to make a suitable tool by cutting six notches in the end of a steel pipe. While this was not as good as a real wrench, it was sufficient to grab the points of the nut and stop it from turning, in the manner of a basket strainer wrench (as suggeseted by Jimmy James.).


8 Answers 8


This is a tubular wrench.

Apart from the British "box wrench" term, "tubular" is in my experience the most common generic name for these tools. You can get a full set of them (I have one, though in metric sizes).

It looks like googling "tubular box wrench" is the best way to get the right stuff while eliminating the American meaning of "box wrench".

  • Thanks - this combination of terms picks out this type of wrench specifically. It seems that my difficulty in finding them in the USA is that, except for the specific purposes already mentioned, they are not readily available.
    – sdenham
    Jan 14, 2021 at 13:19
  • I think I have one or two. They came with plumbing fixtures, I think.
    – JimmyJames
    Jan 14, 2021 at 19:49
  • 2
    I'm struggling to imagine a use case where a socket set and extension wouldn't work and this would. I assumed these were just added to packages in case the purchaser didn't have real tools like those little flat stamped wrenches.
    – JimmyJames
    Jan 14, 2021 at 19:55
  • 1
    Never mind, I figured in out. A basket wrench might be an alternative though.
    – JimmyJames
    Jan 14, 2021 at 20:02
  • @JimmyJames use case ... -> I have a large double ended one of these. It fits over the two standard size elements and thermostats used here (NZ) in hot water cylinders. It need to be large in dia to fit AND deep to accommodate the electrical fittings which extend from element and thermostat. A socket that did the job would be very heavy indeed and probably priced at $100 plus - unless it was made lightly as a custom solution for this job - and then you'd need two of them. Jan 15, 2021 at 11:45

There are some that are made for removing and installing faucet valves.

Shower valve socket wrench.

  • This has the same problem as "spark plug wrench": made for a specific purpose, there are only a limited set of sizes. I have such a set and have tried them.
    – sdenham
    Jan 13, 2021 at 19:47
  • Pass through or bolt through socket?
    – Alaska Man
    Jan 14, 2021 at 20:03

That's another

Disposable Wrench

or possibly

Disposable Tube Wrench

Cheaply stamped out of metal tubing, they are sold with products for the single use of installing that product then discarding. You can find them often with furniture and fixtures.

  • I was just about to add this to my answer, but you've got it covered. I find that most of the one's I've got have come with something else for assembly of that thing. I do believe I may have received one with our last lawn mower for installing the spark plug, thus lending credibility to the OPs "spark plug wrench" findings.
    – FreeMan
    Jan 14, 2021 at 11:42
  • @Feeman I had actually purchased a "spark plug wrench" to do maintenance on my motorcycle.
    – Aleks G
    Jan 14, 2021 at 15:59
  • AKA, garbage, +1. So you should leave it behind in the base cabinet, or put it in the box of house parts.
    – Mazura
    Jan 15, 2021 at 1:51

One set I found calls it a "Valve Socket Wrench".

No recommendation of brand or vendor implied or intended

  • I was going to add this as I have a set on a wire keeper also they may not work for a tough pipe at 1-1/4”
    – Ed Beal
    Jan 13, 2021 at 21:33

These are also known as a box wrench.

  • Unfortunately, searching for "box wrench" on Google, DuckDuckGo, Home Depot, Lowes and Harbor Freight gets the same result as I described for "box spanner". If you know of ayone selling these items as box wrenches or anything else, a link would be much appreciated! (maybe they are just not made anymore, except for spark plugs, shower valves and water heater elements?)
    – sdenham
    Jan 13, 2021 at 22:32

That's a spark plug wrench. Mostly used on 2 and 4 cycle engines. Chainsaws and trimmers where the plug is recessed this type of wrench is necessary for maintenance.

  • I had one exactly like the picture, in the tool kit that came with a 1967 Honda motorcycle There was also a rod to insert through the holes to apply torque. Jan 14, 2021 at 7:32

Not directly related to your question, but you mention in the comments that there is limited side access and you will need a lot of force to be applied.

Be aware of things called "crows foot" wrenches. These are commonly used in HVAC and heavy equipment (hydraulic) maintenance. crows foot wrench

The wrench is a combination, made up of a "wrench part" and a standard ratcheting handle plus zero or more extension bars to provide depth offset. The wrench part looks like an open-ended wrench with a cut-off handle, where the stub of the handle has a square hole punched out for the ratchet handle to plug in.

For "flared fitting" work -- usually gas piping -- the open-ended wrench may actually have stubs on the ends of the arms, as shown in the photo. General-purpose crows-foot wrenches don't have these stubs, and just look like stubby open-end wrenches.

These wrenches do require a certain amount of space right next to the fitting or nut. But they allow offsetting the lever arm, and they allow using a torque wrench if you desire. As with any ratchet wrench, you can get a truly obscene amount of torque going with a "cheater bar" and a sacrificial helper to hold things steady.


As a general term I would refer to these as "Tubular socket wrench"

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.