Cross Threaded – What Is A Cross Threaded Bolt?

by Conner Mckay

Have you accidentally cross threaded the lug nuts on your car? Well, if that is the case, then you are at the right place because there will be a lot to cover on this topic and learn how to overcome this problem.

Having a problem like this can really be a frustrating thing to deal with because you are basically ruining both the bolt and the hole into which you place this bolt. This will result in a bolt that simply doesn’t want to sit properly as well as a bolt that will fall off sooner or later.

And frankly, you don’t want to have a bolt like this on your car. Bolts should be one of your top priorities when it comes to your car. You should always pay attention to how you tighten up the bolts because if you don’t do so, you will pay hundreds on retreading a bad bolt and fixing the problem. This is why we are going to help you out.

First, we will cover some of the basics and learn more about what is a cross threaded bolt in general and what happens in this situation. Then we will learn the main causes of this type of bolt damage. Then we will cover the types of bolts that often get cross threaded and after that, we will learn how to remove a stuck bolt and how to refinish the threads. So, if you want to learn more, follow along.

What Is A Cross Threaded Bolt?

Now before we dive into more complex topics, let’s first discuss the basics and learn what is a cross threaded bolt in general. Knowing this will help you when it is time to diagnose this problem and understand if you have a bolt like this on your car. If you are up to the task and learn more about what are the causes and how to remove one, you can jump to the next chapters, if not, keep up with us for a bit.

So, what is a cross threaded bolt? Well, this is a bolt that has not been screwed in place as it should be. Meaning that it was screwed at an angle or by force.

And this type of screwing will basically screw up your bolts. Not to mention that the bolt hole will also get damaged and you will need to resurface this hole in order so the new bolt doesn’t get cross threaded.

So, you can see if you do this practice, not only the bolt but the hole with the threads will also get mangled up and destroyed in the process.

And this is rather expensive to fix. Even though the bolt holes usually are made from a much harder metal than your regular lug nuts, they could still get enough damage not to allow the bolt to be screwed in place properly. So, in order to get rid of this problem, you will have to resurface the hole as well.

And when it comes to the bolt itself, this bolt is a scrap metal. You should replace it at any cost because it will not work well anymore. But more on that in the next chapter where we will learn what happens if you have cross threaded bolts.

What Happens If You Cross Thread A Bolt?

Now let’s learn more about what happens if you cross thread a bolt. What can you expect to be the outcome of this situation and how the car will behave when you do this type of damage to the bolt?

Well, there is highly likely that you will cut new treads into the bolts. This means that the bolt will not fit ideally and it will get inside the hole at an angle.

So, you cannot expect to bolt in the nut ideally, it will be an imperfect fit and you will have a ton of troubles with this type of bolt. But why is this the case?

Cross Threaded

Well, this will be the case because the bolt will not go all in, resulting in a poor fit and vibrations will be one of the first things that you are going to notice in these situations since the bolt will not be ideally mounted in its place.

This could lead to breaking off the stud under heavy loads and your engine up with a broken bolt. So, proper removal of this bolt and resurfacing will be needed in order to fix this cross threaded bolt hole.

So, what is important for you is to never force a bolt to go in the hole. The more you force it, the worse it will get and this will result in creating new threads and ending up with a cross threaded bolt. But more on this, we are going to cover in the following chapter, where we will learn the most common causes for cross threading and you ending up in this situation. And you don’t want to miss that.

Causes For Cross Threading

Now let’s move on to something more interesting and learn more about the causes for cross threading.

As you probably know, everything happens for a cause, and knowing these causes will help you prevent ending up with cross threaded bolts on your car and a ton of headaches. So, if you want to learn more, follow along.

1. Bad Insertion Angle

Now let’s cover the first cause for ending up with cross threaded bolts on your car. And that is the bad insertion angle. This type of cross treading is called angular cross threading.

This type of damage occurs when the work is usually done by inexperienced people who are careless and try to install the bolt at any cost.

Mostly by running the power tool from the start and ending up with cross threaded bolts in the end. You should never do this. Unless you want to ruin the bolts on your car.

When you try to apply a bolt, first you do it by hand. And after the bolt was placed into position, you can move on to using a power tool in order to tighten up the bolt.

Even though in some cases you don’t have to use a power tool to mess up the treads. You just need to be careless enough and not be aware of the angle at which you apply the bolt.

Bolts are usually made out of soft metal and their treads can easily end up cross threaded. So, beware of this situation when you apply the bolt. Now let’s move on to the next probable cause.

2. Improper Thread Pitch

Now let’s cover the second most common reason for ending up with cross threaded bolts. And that is using the wrong thread pitch. Also known as parallel cross threading.

Usually, when you install a bolt that you previously removed from the car, you know that the pitch is good.

But there are situations in which you install a bolt into the car and you don’t know the exact pitch of the bolt that should install. But what is a bolt pitch in general?

Well, a pitch in simple words is the space between the treads. Some bolts even though they fit in the hole, do not have the same pitch as the grooves in the hole.

So, when you try to install a bolt that does not have the right pitch, you will end up with a cross threaded bolt.

This is why you should try to tighten the bolt by hand first and then see if it goes in. If it doesn’t then this is a situation where the pitch is bigger or smaller than expected. You should avoid tightening the bolt by force unless you want to damage the threads and ruin the bolt.

So, when you install a new bolt, make sure that you have the right pitch and if you mistakenly get a bolt that has the wrong pitch, don’t force the bolt in unless you want to create parallel cross threading and ruin the treads. Now let’s move on to the last cause of ending up with the cross threaded bolt.

3. Rust Development On The Bolt

Now let’s cover the last cause for ending up with cross threaded bolt and that is the rust development inside of the bolt or the treads that you want to mount this bolt on.

If you want to mount a new bolt on some old rusty engine that has treads full of grease, dirt, and rust, you shouldn’t rush. Why I’m saying this?

Well, I’m saying this because in most cases, the bolt housing is rusted out and has a ton of dirt. So, in these situations, you should play it smart in order to avoid some damage being done to this bolt and end up with the cross threaded bolt.

Before you decide to tighten up this new bolt in place. You should clean the threads. There are special tools that can be used for this purpose.

Also, you can apply some grease to the bolt so it bolts on without a problem. If you decide not to do this, you will end up damaging the new bolt.

Not to forget to also use a thread locker in order to make sure that you do this job the right way. Especially if you install something like a head bolt. These bolts need to be really tightened up to spec if you want to avoid them loosening up and you end up with a head gasket issue. Now let’s move on to the next topic and learn more about the types of bolts that get cross threaded.

Types Of Bolts That Get Cross Threaded

Now let’s dive into the different types of bolts that usually get cross threaded. So, you get a better perspective on which bolts you should pay attention to when you tighten up these bolts.

Knowing the most common errors will save you hundreds of dollars on retreading and sorting out the problem on your vehicle. So, let’s cover the most common ones.

1. Cross Threaded Lug Nut

The first type that we would like to cover is the cross threaded lug nut also known as a wheel bolt. A lot of people are using power tools to remove and install these bolts.

Sometimes they don’t put any effort into making sure that they install the bolts properly. So, they just put the bolt in its place and spin the power tool, and damage all the treads.

And this is a bad practice. Especially if we are discussing lug nuts. These nuts keep your wheels onto the car and if you are using these methods you are basically risking your own safety. So, beware not to end up with a cross threaded lug nut on your car.

Make sure that you clean the treads before installation and then torque them to the right spec. If you don’t do this and you torque them with too much force you will end up facing symptoms of over-tightened lug nuts. Now let’s move on to the next bolt type.

2. Cross Threaded Spark Plug

Now let’s cover the second type that is really common and that is the cross threaded spark plug. Spark plugs have treads and frankly, it is really easy to mess them up.

And when you mess up a spark plug you are ruining the cylinder head. So, a specialist needs to retread this damaged plug treads.

Whenever you are dealing with plugs, you need to be aware that in most cases you are dealing with really soft metal. Cylinder heads are usually made out of aluminum. So, if you try to force the spark plug in its position, you could end up damaging the treads.

It is a smart idea to clean off the threads before you decide to place the spark plug and always make sure that you follow the right angle. Because if you don’t, you will end up with cross threaded spark plug.

3. Cross Threaded Oil Drain Plug

Now let’s cover the last type that is really common and that is the cross threaded oil drain plug. There are a ton of people out there who are really careless when they remove the drain bolt and do not care about the bolt and whether or not they damage something.

But to make things even worse, when you cross thread this bolt, you end up with an oil leak. The pan will leak and if you are careless enough, you will end up with a leak.

Then if you do not follow this leak and you basically allow all your oil to leak out, you will end up with engine damage. So, when it comes to avoiding a cross threaded situation, make sure that you follow the tips that we will share in the following chapter.

Tips To Avoid Cross Threading

Now let’s cover some tips when it comes to preventing ending up with cross threaded bolts. The first thing that you need to focus on is keeping the threads clean. Number two thing that you need to make sure that is if you have a cross threaded bolt, you should replace it. Never reuse a bolt that has been damaged to a certain extent. This bolt will never be the same.

If the threads are damaged, make sure that you resurface and restore them. More on this we will cover in the following chapter how this work is done.

The next thing you will need to make sure of is to use a bolt with the right pitch. If you use a bolt with a bigger pitch than your factory recommended spec or with a smaller pitch, you will end up with cross threaded bolts on your car.

Cross Threaded

Another thing to add is whenever you try to screw a bolt, you always need to make sure that you get the proper angle. The angle is one of the most essential aspects when it comes to screwing a bolt in its place.

And the last thing that we would like to cover is not to be persistent. There are people out there that want to make the bolt get in place by using force. And with this mindset, you will not get too far. When it comes to bolts, you need to be really calm.

Whenever a bolt doesn’t want to go in, there is a problem with something, and this problem needs to be checked, either there is dirt, rust, or possibly you are using a wrong pitch. You need to focus on these things if you don’t want to end up with a cross threaded bolt.

How To Restore Damaged Threads?

Now let’s move to an interesting topic and that is how to restore damaged threads. Now let’s imagine that you cross threaded the bolt on your oil drain plug. How you can restore the treads on the oil pan and make sure that the bolt seals well?

Well, for this practice, you will need a special retreading kit. This kit is available at most online stores and you can get one for a really good deal.

In this kit, there are a ton of refinishing tools for all the different bolt sizes. So, don’t wait and grab one for yourself if you want to sort out this problem with a cross threaded bolt. But how you can use it?

Well, the first thing you will need will be to drill out the hole that was cross threaded. You can do this with a power tool and a drill bit.

Once the hole is cleaned, you can start using the tool from the kit. With this tool, you will be able to create new threads on the oil pan. Just beware that the same size bolt will not fit again in this place. So, you will have to get a bigger bolt to replace the damaged bolt on your car.

In the video that we attached above, you can see how this procedure is done on a cylinder head. But the procedure is almost the same on any application. But let’s say that you want to fix this problem at a shop, how much can you expect to pay to fix the cross threaded lug nut? Let’s elaborate more on that next.

Cross Threaded Lug Nut Repair Cost

So, how much can you expect to pay in order to fix the cross threaded lugs on your wheels? Well, this will cost you some money.

Nobody is working for free but still, you cannot expect that you will pay a ton of cash to fix something simple like this. In the worst case, you will pay up to $15 to fix the problem with your car’s lug nuts.

If you want to go for the cheaper route, you can try retreading these treads by yourself using this kit that we mentioned in the previous chapter. Now let’s conclude this article.

Cross Threading Facts

  1. Cross threading can occur on any bolts or screws during various tasks like rehanging a door or reattaching a wheel on a vehicle.
  2. Cross threading happens when a fastener like a bolt or screw is inserted into a pre-drilled hole at an angle instead of perfectly aligned with the threads.
  3. Angular cross threading occurs when the tip of the bolt or screw is turned before being aligned with the threads in the hole, causing misalignment and eventual failure of the thread.
  4. Parallel cross threading occurs when the alignment of the two parts is twisted together during initial mating, commonly occurring when power tools are “over-torqued”.
  5. Cross threading can cause the fastener to become stuck and destroy the pre-drilled hole, making it difficult to fix.
  6. To avoid cross threading, it is important to ensure that the fastener is clean before insertion.
  7. Starting with fingers can help determine if the movement of the hole and fastener are aligned properly before using a tool.
  8. Starting by turning the screw the wrong way (counter-clockwise) before turning it clockwise can help ensure that the start of the hole and the tip of the fastener are lined up.
  9. Cross threading can be a real problem when trying to put two things together and relying on the fastener.
  10. Angular cross threading is a more common form of cross threading than Parallel cross threading.

Conclusion

In this article, we covered quite a bit when it comes to cross threaded bolts. We learned what they are and the causes of why they happen.

Then we covered the most common situations when they occur and which bolts are most affected by this problem. Lastly, we shared some tips on how you can avoid this problem in your car.

F.A.Q

Now let’s answer some frequently asked questions.

What Does Cross Threaded Mean

Cross threaded means that the threads were retreaded in crisscross pattern. And this isn’t the way it should be. The threads need to follow a single pattern. Anything except this will mean that there is a damaged bolt that needs to be retreaded.

Will A Cross Threaded Bolt Hold

In most cases, it will hold but not to a great extent. It could fail all of a sudden and cause a ton of vibrations that will cause it to fall off from the hole. So, you need to make sure that you retread this bolt.

How To Rethread A Bolt Without a Rethreader

This unfortunately is not possible. You need to have a special tool in order to retread the bolt to the desired size. If you don’t use something that is not made for this purpose, even if you retread it, it could not fit the hole or the extent of the damage to this bolt will not allow this bolt to hold.

How To Fix Cross Threaded Bolt

The best thing would be to replace this bolt. A bolt hole can be retreaded but a bolt could not be retreaded, unfortunately. If the bolt is damaged, then get one from the hardware store and replace it.

How To Fix Damaged Threads

You can fix damaged hole threads by using a special kit that was designed to retread bolt holes. With this tool, you will be able to finish this job really fast without any big issues.

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