Strength Test: Plexus® MA422 Vs. Infinity Bond MMA 422

May 5, 2025

There are a large number of adhesives with similar properties and performance capabilities. For many businesses, it is easiest to just keep using the same adhesive that they have always been using, but they could be missing out as a result.

To help, we put two similar methacrylate adhesives to the literal test with a lap shear strength test. The first adhesive is ITW Plexus® MA422. This product comes from the popular Plexus brand and is widely used. The second product is Infinity Bond MMA 422. This product has a very similar formulation with the same capabilities but is not as well-known as the Plexus product.

Our test is designed to see how the two compare specifically in terms of lap shear strength, but we also compare Plexus MA422 and Infinity Bond MMA 422 as a whole to give you the full picture.

Running the Tests

These tests were conducted by one of our adhesive application lab assistants at an ISO 9001-certified lab. The test itself follows ASTM D1002 guidelines for high-quality and replicable results.

The ASTM D1002 test uses aluminum metal substrates that are scuffed, cleaned with isopropyl alcohol, and left to dry to ensure the adhesives can form a proper bond to them. The adhesives are then dispensed onto an aluminum substrate and another piece is pressed on top overlapping by half an inch. For consistency with each sample, glass beads are used to ensure a 10-milliliter layer of adhesive between the two substrates. These bonded pieces are left to cure overnight in an oven.

The lap shear test itself involves putting the bonded piece in a universal testing machine that will slowly pull the pieces apart until they experience adhesive bond failure. The machine records the force it took to reach bond failure in pounds per square inch (PSI) and newtons (N). Three samples for each adhesive were tested, and the averages of the results were calculated to compare the difference between Plexus MA422 and Infinity Bond MMA 422 regarding their lap shear strength.

The Results

After all six samples were tested in the universal testing machine, we found the following results:

We found that Infinity Bond MMA 422 performed better than the Plexus methacrylate. On average, the Infinity Bond product experienced cohesive failure at around 6005 newtons or 2700 PSI. In contrast, the lap shear strength of Plexus MA422 was lower as it took an average force of 5544 N or 2492 PSI to experience cohesive failure. This equates to the Infinity Bond MA 442 adhesive requiring on average 461 N or 208 PSI more force to experience bond failure.

More Details

After looking at all the samples, the results were clear. Infinity Bond MMA 422 consistently had a higher lap shear strength than Plexus MA422's lap shear strength. On top of the difference in strength, our team has also done a more in-depth review of Plexus MA422 in the past and also spent some time reviewing Infinity Bond MMA 422.

In comparing Plexus MA422 and Infinity Bond MMA 422, we found that the two products have very similar chemical makeups and capabilities. Both are 10:1 methacrylates with great impact resistance that are used to bond substrates like metals, composites, and thermoplastics. They have very similar work life times with Infinity Bond at 18 to 24 minutes at 75°F and Plexus at 17 to 20 minutes at 75°F. Both also boast a high resistance to hydrocarbons, acids, and bases. Considering these many similarities, this difference in lap shear strength could be significant for applications where great strength is required.

On top of the difference in strength, there is also a big difference in price. After a quick search online, our team discovered that the price of Plexus MA422 tends to be significantly higher than the price of Infinity Bond MMA 422. So, for businesses already using this Plexus product, they could be paying more for less strength.

Let's Review

After reviewing the similarities and differences between Plexus MA422 and Infinity Bond MMA 422, you may be ready to make the switch. If you want more information or to confirm that Infinity Bond MMA 422 is in fact a good choice for your application, contact us. Our team of adhesive experts will work to answer your questions and offer help as needed.