How Strong Is Epoxy Adhesive (And How It Compares To Others)

Epoxy adhesives are perhaps one of the strongest commercially available types of glue. They are used in aerospace manufacturing and for application where maximum strength and resistance is required.

All of that tells us that these adhesives are strong, but how strong they actually are.

In this article, we will look at the strength of the epoxy adhesives in a clear and easy-to-understand fashion.

We will also compare the strength of these adhesives to other popular ones so that you can get a better understanding and perspective of their everyday strength.

How Stong Is An Epoxy Adhesive

Epoxy adhesive is designed and used for heavy-duty projects and repairs where extreme structural strength is required. But what kind of applications are those, and how can we measure their strength.

The strength that is usually advertised when we shop for these adhesives is the tensile strength. The tensile strength is expressed in PSI which stands for pressure the adhesive can withstand in pounds per square inch.

Epoxies have one of the highest PSI’s of all adhesives, and they can exceed over 6000 PSI. Most commonly you will find epoxies in a 4000 to 5500 PSI range.

To give you a better understanding of the actual strength that those numbers represent, let’s take a look at a little example.

5000 PSI Pounds epoxy from J-B Weld can hold a compact truck per square inch. That’s how strong this adhesive is.

But tensile strength isn’t everything. Super glue also has massive tensile strength but lacks the sheer strength that makes the adhesive structurally strong and resistant.

Epoxies are known to have massive shear strength along with a great tensile strength which makes them withstand any type of pressure from all directions.

This combination of high shear and tensile strength makes the epoxy a terrific choice for fixing heavy-duty and high-stress structures.

It is extremely resistant to pressure and is an adhesive that will hold the bond no matter what.

How Does It Compare To Other Adhesives

bottle of glue

The strength of the epoxy adhesive is unmatched in today’s market. You will have a hard time finding a stronger and more resistant adhesive than a high-quality 2 part epoxy.

As we previously mentioned, epoxy is similar to cyanoacrylate or super glue in terms of tensile strength but is miles ahead in shear strength that is required for a good overall structural strength of the adhesive. This actually shows you how strong is super glue, and how strong epoxy is.

Polyurethane adhesives are perhaps the closest in terms of strength to the epoxy resin. They are just behind in both tensile and shear strength to this glue but offer high strength indeed.

The advantage of polyurethane adhesives is the extreme environmental resistance they provide. Epoxies don’t have that kind of resistance to environmental factors but are suited for projects where more strength than water and heat resistance is required.

Common construction adhesive can be 5 times weaker than epoxy adhesive. They are made to be affordable in large quantities where a lot of glue is applied to large surfaces. Epoxies are intended for smaller projects in terms of size but higher in terms of structural strength.

Should I Use Epoxy

Whether or not you should use epoxy largely depends on the strength and the difficulty of your project.

For simple mend of a broken ceramic vase, an epoxy adhesive is an overkill, and this is where super glue would do just fine.

For projects where extreme structural strength is need, such as vehicle and building repairs, epoxy performs the best. Bonding heavy-duty materials like stone to metal are best done with epoxy glue.

The excellent water resistance and harsh weather tolerance make it perfect for boat, car, and aircraft repairs.

Some epoxies will provide you with a bond that is equal to or stronger than torch welding which speaks of its extreme strength.

There have been a number of cases where people have decided that they were not going to pay enormous fees for their vehicle repairs and fixed their problems with epoxy instead.

Those repairs were as good as those done by a professional because of the massive strength and resistance of this adhesive.


Epoxies are the strongest of the strong. They are the adhesives to go for when you need a heavy-duty fix.

The combination of extreme tensile and shear strength makes it one of the strongest adhesives today.

If you can benefit from the massive strength of this glue, there is no better option on the market.