adhere academyMany of our material product data sheets (PDS) will quote a number for the modulus of elasticity.

The modulus of elasticity is a number which represents the material’s tendency to be deformed elastically (i.e. non-permanently, recovering original size and shape) when a force is applied to it.  A stiffer material will have a higher modulus of elasticity, a softer material will have a lower modulus. We use units like MPa or psi for this number.

There is a relationship between modulus of elasticity and hardness. Hardness is a measure of how resistant a material is to various kinds of permanent deformation or shape change when a force is applied.

These physical characteristics are useful when selecting an adhesive, coating or other material. Let’s look at two or our most popular UV curing glass bonding adhesives:

Name Modulus of Elasticity Hardness
Dymax 429 67 MPa Shore D60
Dymax 6-621 730 MPa Shore D80


Both of these products bond glass to metal very well. If you want a hard, rigid, clear bond – then Dymax 6-621 is a good candidate. But if you have a large area or high-impact application, where a flexible adhesive would be desirable, then Dymax 429 is a better one to test.


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