Where and How to Attach Safety Chains

What are the best ways to attach safety chains on a trailer?  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 us look at some bad ideas and learn, then at some good ideas.  We will learn good technique by evaluating bad.  Ah, but First, the goals.

Why Safety Chains?

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

While this may be a dumb place to start, we will give a quick nod to why we have them in the first place.  One, because it is the law.  Two, because it is part of being responsible when towing.  And Three, to compensate for our own oops.  Read more in this article on Trailer Safety Chains.

Crash Did Not Have To Be This Bad
Interesting photo.   I do not know the circumstances, but one safety chain is loose, and the other is much too long.  Look at the distance from hitch to coupler.  This accident did not have to be this bad.

A Fourth, is (hopefully) an extreme rarity — to save your own life.  Read about dangling by a single trailer chain.

The point of asking “Why Safety Chains?” is to make sure as we attach them, so we do not thwart the reasons for having them in the first place.  If the reason for having them is to keep the trailer connected in the rare event a hitch disengages, then the attaching must do the job if we need it.  Unfortunately, that is the purpose of the article.  So many chains attach in ways that will not accomplish the task if you need it.

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

Things To Avoid As You Attach Safety Chains

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 the violent event.  Please, question what you see and hear – EVEN in this article.  If things are contrary to sound thinking, disregard them.

OK, we will get on with it.  We can start with learnin the GOOD by evaluating BAD.  Here are some BAD examples:

Wimpy, Wimpy, Wimpy

Hopefully this one goes without saying:  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.  That means for a 7,000 lb capacity trailer, each chain must have a break strength greater than 7,000 lbs.  With 2 chains, that is 14,000 lbs total.

Chain Break

Please Note:  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 where the chains hold a load, like binding a load onto your trailer.  Think logging chains.  For safety chains that attach at the hitch, 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.

So, our First Rule:  Choose chains that are STRONGER than the total weight capacity of the trailer.  Attach safety chains in ways that are stronger than the chain.  Hooks and connections should all be stronger than the chain too.

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?

Trailer Safety Chain Connection At The Tongue
Connection Loops are right at the bottom.  If this hitch fails, the chains are first to contact the ground and grind off.

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.

Second Rule:  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 – I do not know about their strength (see below) – 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.

Attach Safety Chains By Welding
Links of the chain attach by weld directly to the trailer.  True, they will not accidently fall off, but welding heat weakens the links.

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.

Chain Link Weld
It is a nice weld. Yet, it is not the weld that is concerning. It is the change in material properties, and now this is the weakest link.

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

Third Rule:  Do not weaken the chain while 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 so much.  However, if you bought a chain rated for your trailer, why weaken it?  Just consider the situation and do not make this rookie mistake.

How Long?

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

Trailer Hitch Chains That Are Too Long
An example of Trailer Safety Chains that are too 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.)

Fourth Rule:  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.)

Trailer Safety Cables

What is Wrong in the photo?  1.  Hopefully you see the connection point on the tongue that will grind when it hits the ground.  2.  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 you can say the same for bent chain links.  3.  The bracket for attachment is weaker than the cables.  4.  The cables are much too long.

Fifth Rule:  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 info.


Now The Good Ways To Attach Safety Chains

We have learned from some mistakes above, now we will look at some MUCH BETTER ways to attach safety chains.

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.

Attach Safety Chain With Bolts

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

Does it follow the rules?  1)  Choose chains that are strong enough.  2)  It will not grind chains on the ground.  3)  It does not weaken the chain, and the mounting (grade 8 bolts of of max diameter) is stronger than the chain.  4)  It is easily adjustable, so chains can be short.  5)  Direction of forces are in line with the chain.  (I will note, 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, the 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.

Attach Safety Chain With One Bolt

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).

Simple Bolt Tabs

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)  It will not grind chains on the ground.  2)  It does not weaken the chain, and the mounting (heavy steel tab with grade 8 bolts) is stronger than the chain.  3)  It does not adjust, so chain length will have to be set carefully.  4)  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.

Double Tab Adjustment to Attach Safety Chain

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)  It will not grind chains on the ground.  2)  It does not weaken the chain.  Mounting (with grade 8 bolts and double steel tabs) is stronger than the chain.  3)  It is easily adjustable, so chains can be short.  4)  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

If you like this design, 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 like it is 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.

Link Lock Installed
This is the Link Lock system properly installed.  Image is from the Link Lock Facebook page.

Does it follow the rules?  1)  It is made to adjust easily, so it will not grind chains on the ground.  2)  It does not weaken the chain.  3)  It is easily adjustable (the easiest I have seen), so chains can always be the right length (from the car to the trailer).  4)  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 product.

Another Pinned Product

Simple Way To Attach Safety ChainsAlong 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)  If it mounts on the side of the tongue, then it will not grind chains on the ground.  2)  It does not weaken the chain, and the mounting is solid when welded as intended.  3)  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.  4)  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?

Finally, our current best recommendation is the method in this article “Simple Chain Anchor System – Free Plans“.  Enjoy.


Now The Test !!

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

New Chain LoopHere 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 safety chains attach.

The Test

In context of all the rules above, what do you see in this photo?

There is another photo below showing 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 did you come up with?

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

OK, time is up.  Let us look at the answers.

Answers to Attach Chains For Safety

Safety Chains Wimpy Attach
Here is what I see:

  1. To Rule 1 – The chains look beefy, and the hooks appear as a good size for the trailer.  Pass.
  2. To the other part of Rule 1 – This loop is NOT stronger than the chain.  It is the same diameter material, but it is soft, and it is welded – the front bit not by much.  This is the weak point.  FAIL.
  3. To Rule 2 – They attach the safety chains to the bottom of the beam.  We could argue that the hitch extends below so the chains would not grind, and I will accept that.  The jack will rip right off, but the hitch is very tough.  Pass.
  4. To Rule 3 – Mixed bag.  They did not weld the chain, so that is good.  Pass.  However, as noted above, the loop is the same diameter material as the chain, and because it is on the chain it is effectively a link.  If you are going to weld it on with a loop or some other piece, make sure it is bigger so when it is weakened by welding, it will be at least as strong as the chain.  Overall, FAIL.
  5. To Rule 4, we do not know without a tow vehicle.  I will say, however, that the attach point is close to the hitch, so that is good.  Pass.  They look long to fit most anything, but we will not knock that since we do not really know.
  6. Unofficially, with Rule 4 it is not hard to make the chains adjustable so the customer does not have to come up with something else.  That is a Fail from a customer service standpoint.
  7. To 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?  Leave a comment.

Thank You For Considering How To Attach Safety Chains

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

There is really no reason to compromise with safety chains.  Yes, they can be a bit of a hassle, but when you need 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 new “Show Me” search field at the top of the page.  Just type in a question and we will show you what we have.

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