Epoxy Resin Hardness: How Strong Is Epoxy Resin?

Do you know the hardness rating of your epoxy resin?

The hardness rating, or Shore Rating, can help to determine whether a particular epoxy resin is suitable for your project. If you intend to coat countertops, tables and bar tops , you’ll need a hard-curing epoxy resin with a high Shore Rating to do the job properly.

A rock hard cure is exactly what Industrial Clear epoxy resin was designed for. When prepared according to the label instructions, Industrial Clear cures into a durable coating that lasts for years that can resist scratches and damage from high traffic areas.

How is the hardness of a material measured?

Hardness is measured with a durometer: a device featuring a pointed metal indentor with spring resistance. A durometer works by pressing the spring-loaded steel tip into a surface to measure how resistant the material is, based on the depth of the indentation and the force required to create it.

measuring epoxy's hardness with durometer

What is the Shore Hardness Scale?

The Shore Hardness Scale, created by Albert Shore in 1920, quantifies hardness from 0 (the softest and most flexible) to 100 (the hardest and most brittle) for various materials. Resins are measured on the Shore D scale for rigid materials (as opposed to Shore 00, Shore A, Shore B, etc, which are used for other types of materials).

Chart Of Shore Ratings

Below is a chart outlining the Shore ratings of some commonly found materials.

Shore 00 is for very soft gel materials.
Marshmallows and gummy candies: 10
Chewing gum: 20
Gel shoe insert: 30
Silicone mold: 50

Shore A measures the hardness of flexible rubber materials.
Rubber band: 25
Inner tube: 40
Pink eraser: 55
Car tire tread: 70
Skateboard wheel: 98

Shore D measures hard, rigid materials.
Golf ball: 50
Wood ruler: 70
Hard hat: 75
Industrial Clear: 83
Bone: 90

What is the Shore Hardness rating of Industrial Clear?

Once fully cured, Industrial Clear has a Shore D rating of 83, meaning it is very firm and durable, but not brittle. Industrial Clear was intentionally formulated as an ideal choice for countertops, tables, bar tops and other applications that need to withstand the wear and tear of everyday use. It’s important to note that epoxy resins harden up over time, so while Industrial Clear feels hard to the touch after 24 hours, it reaches its absolute full cure at 48 hours.

Is epoxy harder than glass?

Glass is typically harder than epoxy resin but is considerably more fragile. In contrast, epoxy resin provides the same glossy and crystal-clear appearance as glass but with greater durability. Resin's natural flexibility means it can better withstand impact and is more likely to bend than break, unlike glass which can shatter. Epoxy resin is more susceptible to dullness and scratches, however surface damage can be fixed by applying a fresh layer of resin on top.

Is epoxy as strong as steel?

While not as strong as steel, epoxy resin does offer a number of notable advantages. Steel is susceptible to erosion, with deep scratches causing rust and corrosion issues even on coated steel.

In contrast, epoxy resin is resistant to rust and corrosion and impervious to moisture, chemicals, and bacteria. Furthermore, its strength makes it a viable alternative to welding and soldering. A potential drawback, however, is its tendency to become brittle in extremely cold temperatures.

Nonetheless, epoxy composites are quickly emerging as the strongest materials available, surpassing conventional options like steel, and are being increasingly utilized for constructing and reinforcing structures.

Is epoxy stronger than glue?

Although glue is widely considered the go-to, epoxy resin is a highly effective adhesive, creating a hard, strong bond between materials. Unlike glue which is typically made from natural materials such as gums, epoxy resin is a synthetic material intentionally formulated to resist moisture, heat, chemicals, and weather. This makes it more durable, longer-lasting, and able to create a bond that can withstand greater force and stress compared to traditional glue.

It's important to note that, while glue bonds porous materials such as clay and wood together well, whereas epoxy resin tends to soak in. A good solution is to seal porous materials first, creating a barrier that will prevent epoxy from absorbing.

Glue also has the advantage of being cheaper and can be applied directly from the bottle without the need for mixing. However, if you have leftover resin, you can easily re-purpose it to fix a number of broken objects around the house, to cover rust on metal, and to seal and waterproof various items.

Is epoxy harder than concrete?

Epoxy resin’s outstanding mechanical properties make it stronger than concrete. Once cured, it becomes almost unbreakable, significantly reducing the chances of cracks or damage from impact or abrasion. Furthermore, cured epoxy requires minimal maintenance and will endure heavy wear and tear for decades with exceptional resistance to chemicals, moisture and bacteria.

One distinct advantage of concrete is that it’s more fire-resistant than epoxy resin. Nevertheless, concrete is more prone to cracking and has poor resistance to chemicals, moisture and mold.

Read about the benefits of using a hard cure epoxy resin.

Industrial Clear: Rock Hard Epoxy Resin