What Is A Carriage Bolt Used For?

Whether you are starting your latest woodworking project or your most recent creation requires something different, a carriage bolt can be a reliable fastener that will help you complete your project and ensure its longevity. One of the biggest benefits of using carriage bolts is the fact that they come in a variety of sizes and materials making it possible for you to find the absolute best option every single time. If you want to learn everything there is to know about carriage bolts then this guide is for you as we will help you better understand how these fasteners can help improve your every project.

 

What is a carriage bolt?
This type of fastener is usually easy to distinguish because of its flat tip and round head. Generally, you will find that its shank is going to be partly threaded but not completely. This is why they are often used for wood applications. On some occasions, you might even come across carriage bolts that are referred to as plow bolts or coach bolts.
However, don’t let the fact that they are mainly used for woodwork fool you. The reality is that because of the variety of different materials that they come in, and because of the different sizes, these types of bolts can actually be quite diverse if you know how to use them.

 

What are Carriage Bolts used for?
As established above, carriage bolts are most commonly used in woodwork. Whether you are looking to fasten a metal piece to a wooden one, or you are trying to join two wood pieces together, the reality is that these fasteners are going to be extremely effective. More importantly, because they lend themselves to the task so well, whatever you create using them will be very long-lasting.
Specialty carriage bolts are also available for those who want to connect two metal components. These are also very common and there are certain industries in which the carriage bolt, is the bolt of choice. The most famous of these include the mining industry, railroad industry, farming industry, and water conservation industry.

 

What will you need for the installation of a carriage bolt?
Unlike a screw, a carriage bolt will actually require a few more tools in order to be installed. This is because it has a flat bottom and no screw head. In most cases in order to properly install one of these bolts you will need to have on hand a nut, washer, hammer, drill, and drill bit.
The drill is always going to be the first step in any carriage bolt installation. This is because carriage bolts should only be inserted in pre-drilled holes because their head is smooth and round. As such, they are unable to piece through any material. Once you have drilled a hole of the correct size everything else pertaining to the installation is going to be easy. All you will need to do is slide the bolt into the pre-drilled hole. On occasion, the hammer will be useful during this process as it will make it easier for you to move a carriage bolt that fits tightly into the whole.
You will also need the washer and nut which will be attacked on the opposite side to seal your fastener. In cases where you are working with wood or fasteners that are a different material, the washer is integral as it will help protect your different materials and reduce the levels of damage. Damage of any type is your worst enemy when you are looking to increase the longevity of your project.

 

What are the differences between Carriage Bolts and other bolts?
You might be wondering why it is necessary to use a carriage bolt instead of a different type of bolt for your project. While all types of bolts might look similar enough, the reality is that they can actually be quite different to the expert eye.
With carriage bolts the main difference to other types of bolts is in the head. The carriage bolt head more closely resembles a mushroom top rather than a hexagonal flat shape which is what is most commonly associated with bolts. If you closely look at a carriage bolt you will also quickly see that there is either a hexagonal shape or a square band that can be seen right under its head. This band will ensure that your carriage bolt is going to completely lock in place when placed into a hole of the same shape.
This function is completely unique to the carriage bolt, as the locking mechanism is not available in other bolt types.

 

What types of materials are carriage bolts made of?

There are a variety of different materials available and depending on your project type and location you might find that some of these options are more appealing and long-lasting for your usage. In general, the main thing you will need to remember is that you should use a material that is not susceptible to rust, tarnishing, or corrosion. The most popular material for this is stainless steel. However, just because it is the most popular it does not mean that it is the only available material.

Often times you can also find bolts that are made of galvanized or zinc-plated metals. These can also work well in certain environments. You should also consider the type of materials you are connecting when choosing the proper material since the interaction between certain types of metals can actually cause them to get damaged a lot more easily and could ultimately result in the quicker breaking down of your project.

 

Why should you choose a carriage bolt?

Carriage bolts are usually the first choice of users who want to ensure the security of their projects. This is because the square neck will help prevent your bolt from rotating and thus going out of its place. However, while this is impressive it is not the only reason for using a carriage bolt.

Carriage bolts are known for being able to support a lot of weight when installed properly. The proper installation of these bolts is also relatively easy, as all you really need is a pre-drilled hole.

Another argument for using carriage bolts is that they reduce the risks of someone trying to remove the bolt. This is because the only way of removing or loosening the fastening is if you have access to the nut side of the bolt. As such, no tool can gain purchase causing the destruction of your project.

 

What are the grades that carriage bolts come in?

The grades of bolts will usually look at a number of different measurements including proof load, yield strength, tensile strength, and Rockwell harness. All of these categories can be essential in determining the grade you have.

The two most common grades of carriage bolts are Grade 5 and Grade 8.

Grade five has a lower load-carrying capacity than Grade 8. However, despite this, its carrying capacity is still quite high when compared to a low-carbon carriage bolt. There is usually also a difference in the material that these bolts are made out of, as Grade 5 carriage bolts are created from medium carbon steel and heat-treated, while Grade 8 is created from medium carbon alloy steel and shares the same heat treatment. Naturally, Grade 8 also has a higher yield and tensile strength.

One of the things that these two grades do share is the fact that they both have the same minimum length of thread which is equal to two times the basic bolt diameter plus 0.25 for bolts smaller than 6 inches and plus 0.50 for those above 6 inches.

 

How can you measure a carriage bolt?

When measuring a carriage bolt to find the correct size for your project you will need to make sure to measure from right underneath the head including the measurement of the square neck. If your measurement does not include the square neck then in reality you are going to face one of the major problems of having a fastener that is the incorrect size for your project.

 

Conclusion:

Carriage bolts are particularly useful in woodworking projects, but that does not mean that their usage is limited to those types of projects. In reality, if you use the proper material and washers there are quite a few options on what you can do with these bolts. The most important thing to remember is that carriage bolts are known for how secure they can be, therefore if you want to ensure that no one can tamper with your project, then these types of bolts are some of the best available on the market.

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