Where and How to Attach Safety Chains

What are the best ways to attach safety chains to a trailer tongue?  That is a simple question without a single best answer.  Don’t you hate it when the answer starts with “It depends . . . “?  Unfortunately, it does depend on many other things – like trailer weight, the construction type, and most important, your biases and priorities.

That said, there are definitely some things to avoid.  So, let’s look at some bad ideas and learn, then at some good ideas.  We will learn good technique by evaluating bad.

This article is about the trailer-side attachment – where and how the safety chains mount to the trailer tongue.  For normal towing, the loose chain ends still connect to the tow vehicle and usually cross under the coupler.

How To Attach Trailer Safety Chains

First, some quick answers to common questions about how to attach trailer safety chains.  Click the question to expand it.  Then, we will talk details below with examples, photos, and engineering insight.

Why Safety Chains?

Safety chains are the most important trailer feature you will hopefully never need.

Before looking deeper at how to attach trailer safety chains, it is worth a quick reminder about why they matter.  One, because they are required by law.  Two, they are part of responsible towing.  Three, they compensate for the occasional mistake, failure, or oops moment.  Read more in this article on Trailer Safety Chains.

A Fourth is hopefully an extreme rarity – to save your life.  Read about dangling by a single trailer chain.

The point of asking “Why Safety Chains?” is to make sure the attachment method does not thwart the reasons for having them in the first place. If safety chains are there to keep the trailer connected in the rare event a hitch disengages, then the attachment must be solid.  It must do the job perfectly if we ever need it.

Unfortunately, many safety chains attach in ways that will not accomplish the task if you need them.  That is the purpose of this article.

Now we will look at some bad ways to attach safety chains to a trailer tongue.

Things To Avoid When Attaching Safety Chains To A Trailer Tongue

I did a few searches on Google and YouTube for attaching safety chains, and I am flabbergasted at things people are teaching.  It is one thing to install chains, and quite another for them to hold in a violent event.  Please, question what you see and hear – EVEN in this article.  If things are contrary to sound thinking, challenge them.

OK, we will start learning the GOOD by evaluating the BAD.  Here are some BAD examples:

Wimpy, Wimpy, Wimpy

Safety chains must be strong.  How strong?  In most places the law says the chain breaking strength must be equal to or exceed gross trailer weight.  So, using a 7,000 lb capacity trailer for an example, then each chain must have a break strength greater than 7,000 lbs.  With 2 chains, that is 14,000 lbs total.  Remember, this is about safety.

Please Note:  For trailer safety chains, pay attention to Breaking Strength, rather than Working Load Limit (WLL).

There are 2 strength numbers for chain.  1)  Breaking Strength is the minimum load that can break the chain.  2)  Working Load Limit (WLL) is the max safe working load for the chain in continuous service.  WLL applies in situations like binding a load onto your trailer.  Think logging chains.  For trailer hitch safety chains, it is the Breaking Strength we look at.

I see a lot of chains that look pretty wimpy.  I cannot verify such, but swing-set chain is not sufficient.  Also, it does not do much good to have strong safety chain if they attach to something wimpy.  More about that below.

Rule 1:  Choose chains and attachments that are STRONGER than total weight capacity of the trailer.  Attach the chains with hardware, tabs, bolts, hooks, and structure that are STRONGER than the chains.

From a legal perspective, each jurisdiction is a little different, so make sure you exceed your laws.  Here is a publication for Trailers in the United States that looks pretty official.

Where Is The Grinder?

Why is this NOT a good way to attach safety chains?

If the tongue of the trailer did come off the hitch, one strong possibility is the tongue would drag the ground.  The event can be violent, and often at speed, so if the tongue does hit the ground, it will immediately start grinding through whatever touches.  So, we do not want something to hit that will dig in, for sure.  But we also do not want to grind off the very thing that is keeping the trailer attached.

Rule 2:  Attach safety chains in a way that they will not grind on the ground if they become necessary.  That means attach chains somewhere other than under the tongue.

In the photo above, the loops may be good for strength – but not in the position shown.

Heat Of The Moment

The next BAD idea is a classic.  This is so common, and it always boggles my mind.  OK, many trailer owners will not know the difference, and I don’t blame them.  However, the person building the trailer is responsible.  If they know enough to weld, then they should know that welding changes the strength of steel – especially tempered steel like chain.  When strength matters, please do not weld directly on a chain.

Steel is not just steel.  There are thousands of steel alloys, each with unique characteristics.  Yet steels change with high heat, rapid cooling, or working (like forging).  Steel is great – some alloys are pliable like a coat hanger, others are hard and tough like a hammer.  While I do not know the exact alloys for safety chain, I do know the links have temper for high strength and toughness.

Chains are strong, but the heat of welding changes the metal.  And, there is no going back.  Even if you cannot see it, the heat anneals the metal, so it is weaker.  Maybe it is still strong enough, or maybe not.

Rule 3:  Do not weaken the chain when putting it on.  Do Not weld chain, and Do Not bend it.

Of course, there are limits.  If the chain is overkill, then maybe it does not matter.  However, if you buy a chain rated for your trailer, why weaken it?  Consider the situation and do not make this rookie mistake.

How Long Should Trailer Safety Chains Be?

How long should safety chains be?  Long enough so it will not bind when turning.  Actually, that is not very long.

Extra length does 2 things:  1) In emergency situations, short chains make it easier to control.  2)  Momentum in motion allowed by long chains creates a bigger impact when a chain comes tight.

Long chains allow the trailer more freedom to yank back and forth, fore and aft.  The tongue can dive under the car, or slam in the back (like the photo above).  It means more damage, and harder to control the violent movement and impact as chains come tight.  If the safety chains attach (on the trailer and tow vehicle) close to the hitch, the chains can be quite short.  That is best.  Please read this follow-up on how to shorten chains.

The hiccup comes with the need to accommodate multiple tow vehicles, and the solution is adjustable length.  (Which is one more reason to NOT weld chain directly.)

Rule 4:  Make the chains as short as practical, and if possible, attach safety chains in a way that allows length adjustment.  If that is not possible, use other “appropriate” ways to effectively shorten the chain.

Awkward!

While cables are a reasonable substitute for chains, they have one very important similarity.  Chains and cables only work in tension.  It is super hard to “push” a chain, and they lose strength if you “kink” them.  By their very nature, chains and cables bend easily, but they are strongest when dead straight.

Look at this photo and see if you can find 2 things wrong?  (There are more than 2.)

What is WRONG in this cable photo?

1. The bracket for attachment is weaker than the cables.
2. The connection point on the tongue that will grind when it hits the ground.
3. The cables are much too long.
4. The cable connection is 90° from the expected forces, so the cables will immediately “kink” if violent force is applied.  A “kink” seriously weakens a cable, and we can say the same for bent chain links.

Rule 5:  Think about the direction of forces.  If chains are violently thrust into action, make sure the things holding those forces are directionally correct.

Another Bad Idea

In the category of “Bad Ideas” we would be remiss if we did not also point out the problems with twisting safety chains.  We have covered that already in this Article on Twisting Safety Chains.  That is important information.

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With the rules in mind, the best safety chain attachments preserve chain strength, protect the chain from road damage, and pull from a strong part of the trailer tongue.  Yes, the methods which obey the rules.

Good Ways To Attach Safety Chains To A Trailer Tongue

We have learned from the mistakes above, now we can look at BETTER ways to attach safety chains.

Spoiler:  If you just want the best … I recommend this Safety Chain Anchor System.  Plans are free, and the examples below explain why the approach works so well.

Bolt Through

Bolting for chains is a mixed bag.  If you support the link and the forces properly, then it is great.  If you crush the chain, use a wimpy bolt, or bolt to a wimpy member, then it is bad.

Here is an application I like from my trailer.  The tongue is 3/16″ thick, and the chain allows a 7/16″ diameter bolt.  Using grade 8 bolts with Nylock nuts and a bunch of modified washers, the attachment is tough.

The 2 through bolts make the chain length reasonably easy to adjust.

Does it follow the rules?

1. Choose chains that are strong enough, then yes.
2. It will not grind chains on the ground.
3. It does not weaken the chain, and the grade 8 bolts of max diameter are stronger than the chain.
4. It is easily adjustable, so chains can be short.
5. Direction of forces are in line.  (However, if the tongue dives under the vehicle, the pull is backward.)

Conclusion:  This one works.

Note:  If you like this system and want the upgrade, see the story about it, then get the chain anchor free plans.

The photo below shows a one bolt version of the above method.  This chain loops under the tongue rather than being cut, yet the loop portion does nothing.  Bolts have special shape washers for spacers to fit the chain.

Bolt Tabs

Special tabs made to attach safety chains are a great solution.  The tabs are very thick, and have a lot of surface area for welding to the tongue tubes.  One hole allows a link sit against the tab for secure bolting.  Again, grade 8 bolts (in the biggest size that will go through the link).

The one drawback, these do not allow easy adjustment.  However, if you do not need adjustability, they are fine.  You can also easily switch for longer or shorter sections of chain as needed.  You can also see the breakaway pin switch on the one side just above the chain.

Does it follow the rules?

1. Assuming proper chain choice, then yes, it is strong.
2. It will not grind chains on the ground.
3. It does not weaken the chain, and the mounting (heavy steel tab with grade 8 bolts) is stronger than the chain.
4. It does not adjust, so chain length must be set carefully.
5. Direction of forces are in line with the chain.

Conclusion:  Overall it does the job well.

Double Tab Bolting

Finally, a double tab with a pin or bolt.  This is a little more complicated to visualize, but it is 2 flat pieces of metal with the chain between.  We attach the safety chain with a pin or bolt, and the tabs are far enough apart that the chain moves easily for quick re-adjustment.

The TABS that weld to the trailer frame are wide so there is a lot of surface area for welding, and so it spreads the chain load out along the tongue tube.  That is a simple way to give extra strength to the system.

Does it follow the rules?

1. With proper chain and material choices, yes for strength.
2. It will not grind chains on the ground.
3. It does not weaken the chain.  Mounting (with grade 8 bolts and double steel tabs) can be stronger than the chain.
4. It is easily adjustable, so chains can be proper length.
5. Direction of forces are in line with the chain.

Conclusion:  This is a robust design.

More images of this and a double version of this concept are near the end of the article on Improving Trailer Safety Chain Connections

The Link Lock System

If you like the design above, but want something configured, try Link Lock.  Their product is similar in concept, but perhaps better in function.  (Note:  I really like their concept, but I have not been able to get a return call from them.  I spoke to someone a few times, but not the person who can answer technical questions.  Multiple promises to call back did not materialize.  Now the website looks unattended, so maybe they are not viable?  Let me know if you find out something.  I would love to buy a set and try them.)

Link Lock Update:

It is worth inserting the Link Lock system here in this section of “Good Ways To Attach Safety Chains”.  I did eventually get one of their systems, and did a complete Review of the Link Lock system in this other article.

Does it follow the rules?

1. Order the right size for your trailer capacity.
2. When mounted properly it will not grind chains on the ground.
3. It does not weaken the chain.
4. The system is easily adjustable (the easiest I have seen), so chains can always be the right length.
5. Direction of forces are in line with the chain.

Conclusion:  The design is great.  If you are looking for an out-of-the-box solution, I have no reservation in suggesting the Link Lock product.

Another Pinned Product

Along similar lines as above, here is another product with a pin attachment for the chain.  It is not amazing, but it is available to purchase.  Do a search.  I found some similar at a few places online.  Since I do not personally know the places, I will not make a recommendation.

Does it follow the rules?

1. Choose the right chain size, and the right connector size.
2. If it mounts on the side of the tongue, then it will not grind chains on the ground.
3. It does not weaken the chain, and the mounting is solid when welded as intended.
4. This device does NOT allow chain length adjustment.  There is not enough room around the pin, so it will only take the end chain link.  However, it is fairly easy to switch chains to one that is the right length.
5. Direction of forces can easily align with the chain.

Conclusion:  Overall it looks pretty good.  Yet, to make it great, you will need to find the right length of chain to fit your trailer / vehicle connection.

More Good Ways

The above are a few good ways to attach safety chains, but this list is not exhaustive by any means.  There are a lot of great ways – just ask yourself:  – Does it follow the rules? –

The rules above are a great test to determine value.  Yes, safety chains can be a hassle, but if you ever need them, they suddenly become incredibly important.  Since we have them, they might as well attach right.

Our Recommended Way To Attach Safety Chains

Our current best recommendation for attaching trailer safety chains to a trailer tongue is the method shown in the article Simple Chain Anchor System – Free Plans.

After all the study and analysis on trailer safety chains, this is the simplest, least expensive way we know to check the important boxes.  It satisfies the needs for strength, chain length, adjustability, and proper force direction.  Yes, it is our creation, yet we give the plans for free because we believe it improves safety.  It is one of the best ways to attach safety chains to a trailer tongue.

Build it yourself for a new trailer, or retrofit it to an existing trailer.  Adjust it to fit your vehicle, then tow with confidence knowing you have the best to keep things safe.

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Test Your Safety Chain Attachment Knowledge

The other day I stopped at a local trailer lot to see some new arrivals.  I was also looking for security ideas, but we will cover that in another article sometime.  (Update:  Check out the Trailer Security article.)

Here is what I found on the front of a 14K trailer.  Yes, there are several things in this shot, but for this article, we will focus on how the trailer safety chains attach.

The Test

In context of all the rules above, what do you see in this photo?  List the positive things as well as things that might be amiss.

The second photo below shows the underside where the safety chains attach.  It is the same on both sides of the tongue.

I have to say, for security, the keys left there do come in really handy!

OK, back to the test question:  What do you see in these photos?

Do you need more time to think?  There is certainly more than one right answer.

OK, time is up.  Let’s look at the answers.

Answers to Attach Chains For Safety

Here is what I see:

1. Rule 1 – The chains look beefy, and the hooks appear a good size for the trailer.  Pass.
2. The other part of Rule 1 – The loop is NOT stronger than the chain.  It is the same diameter material, but not as strong, and welded.  This is the weak point.  FAIL.
3. Rule 2 – They attach the safety chains to the bottom of the tongue beam.  We can argue the hitch extends below, so chains will not grind, and I accept that.  The jack will rip right off, but the hitch is tough.  Not the best, but we will say  Pass.
4. Rule 3 – Mixed bag.  They did not weld the chain, so that is good.  Pass.  However, as noted above, the loop material is the same diameter as the chain, connected effectively as a link.  The loop should be bigger and stronger than the chain so when it is weakened by welding, it will still be at least as strong as the chain.  This FAIL is in both material choice and in attachment.
5. Rule 4 we do not know without a tow vehicle.  The attach point is close to the hitch, so that is good.  Pass.  The chains look long, perhaps too long, but made to fit most anything.  We will not judge that since we do not know.
6. Unofficially, for Rule 4 it is not hard to make the chains adjustable.  Here, a customer will likely need to make changes for their vehicle.  That is a Fail from a customer service standpoint.
7. Rule 5 – The force direction is generally correct.  Pass.

Do you see all that?  Excellent, you are an expert.  Do you see something I missed?  Please leave a comment.

Thank You For Considering How To Attach Safety Chains

We welcome comments.  If you know a good way to attach safety chains, send a note from our Customer Submission page.  Send a photo too, if you can.

There is really no reason to compromise with safety chains.  Yes, they are a hassle, but if you need them, if someone near you on the road needs them, every effort is worth it.

See the Tips Library for more articles, like this one about Good Ways To Shorten A Chain.  Also, try the “Show Me” search field at the top of the page.  Just type a question and we will show you what we have.