Shore hardness laboratory measurement
You need to carry out a Shore hardness measurement on your materials ?
What is Shore hardness ?
Shore hardness is a hardness testing method that involves measuring the penetration depth of a given indentation. This method is one of the techniques used by the FILAB laboratory teams to carry out a hardness test.
The hardness of polymer materials is generally measured using Shore scales.
Principles of shore hardness measurement
Shore hardness measurement is a test commonly used to assess the hardness of materials. It is carried out using a durometer, which applies a force to the surface of the material and measures its resistance to penetration.
Shore hardness measurements range from 0 to 100, with a higher number representing a harder material. The Shore A scale is used to test soft elastomers (rubbers) and other soft polymers. The hardness of hard elastomers and many other polymer materials (thermoplastics and thermosets) is measured using the Shore D scale.
Why measure shore hardness?
Shore hardness measurement is important in industrial and technical fields:
Choice of appropriate material
- Adaptation to stress: Shore hardness is used to select the right material for a given application. For example, for parts subject to heavy loads or abrasive environments, a material with a higher hardness will be preferred.
- Flexibility vs. rigidity: Shore hardness helps to strike a balance between flexibility and rigidity, depending on the performance required. For applications requiring flexibility (such as seals), a lower hardness may be preferable.
Quality control
- Homogeneity of materials: In industrial production, Shore hardness measurement ensures that the materials used meet specifications and are homogeneous, guaranteeing the consistent quality of finished products.
- Defect detection: Unexpected variations in hardness can reveal production problems, such as compositional errors, inadequate curing processes or contamination.
Durability and performance
- Wear resistance: The hardness of a material can influence its ability to resist wear, deformation or mechanical damage. For example, a material with high hardness is less likely to be damaged by pressure or repeated friction.
- Behaviour in extreme conditions: Materials can react differently to extreme conditions, such as high or low temperatures, chemical environments or intense mechanical stress, depending on their hardness.
Compatibility with other materials
- Assemblies and interfaces: Shore hardness helps determine whether a material can be effectively coupled with other materials in an assembly or application.
The support of a laboratory with state-of-the-art analytical equipment for hardness measurement is essential if shore hardness measurements are to be carried out.
Shore hardness measurement applications
Shore hardness assesses the rigidity or flexibility of materials, which are essential for a variety of applications such as rubber, elastomers and seals. It allows each material to be adapted to its specific uses, ensuring flexibility, adhesion or resistance as required.
Shore hardness Elastomer
The Shore hardness of elastomers helps determine their uses. Softer elastomers are often chosen for damping applications or flexible seals. On the other hand, harder elastomers are preferred for parts requiring greater resistance to pressure or chemicals.
Shore hardness Rubber
The Shore hardness of the rubber is used to determine its use. Softer rubber is often preferred for applications requiring flexibility and shock absorption. A harder rubber, on the other hand, is used for parts requiring greater resistance to wear or deformation.
Shore hardness Joint
The Shore hardness of a joint or O-ring determines its ability to provide a good seal. A softer seal is ideal for applications requiring high flexibility, while a stiffer seal is used where stability and resistance to deformation are required.
Shore hardness Polyurethane
Depending on its Shore hardness, polyurethane is used in a wide range of industrial applications. High hardness makes it an excellent choice for structural parts requiring high abrasion resistance.
Shore hardness Silicone
The Shore hardness of silicone varies depending on the application. Softer silicone is commonly used in medical applications. A harder silicone is better suited to industrial applications requiring greater thermal and mechanical resistance.
The FILAB laboratory supports manufacturers in Shore A, Shore D and Shore 00 hardness testing
Through our three levels of services: analysis, expertise and R&D support, FILAB assists companies in all sectors with their laboratory shore hardness measurement needs.
FILAB provides its customers with the know-how and experience of its team, as well as a state-of-the-art analytical laboratory.
Choose between shore A, shore D and shore 00 hardness measurements
There are several Shore hardness scales, but the most commonly used are Shore A, Shore D, and Shore 00 :
Shore A scale :
- Materials: Elastomers, soft rubbers, soft thermoplastics.
- Principle: A conical or rounded tip is pressed against the surface of the material. The softer the material, the deeper the indentation, and therefore the lower the hardness measurement.
- Properties measured: Stiffness and flexibility of soft materials such as elastomers and rubbers.
Shore D scale :
- Materials: Harder plastics, rigid materials such as rigid thermoplastics.
- Principle: Similar to the Shore A scale, but the tip is sharper to penetrate stiffer materials.
- Properties measured: Stiffness of harder, tougher materials, such as rigid plastics.
Shore 00 scale :
- Materials: Gels, soft foams, highly flexible elastomers.
- Principle: A very wide, rounded tip is pressed against the surface of the material. The softer the material, the greater the penetration, resulting in a lower hardness measurement.
- Properties measured: Flexibility and softness of extremely soft and deformable materials.
Shore hardness standards
ISO 48-4 and ISO 48-9 govern the measurement of Shore hardness for specific materials.
ISO 48-4 applies to vulcanised rubbers and thermoplastics using the Shore A and D scales, which are widely used in the industrial and automotive sectors to ensure accurate measurements of stiffness and flexibility.
In addition, ISO 48-9 covers the determination of hardness of the same materials, but with hardness testers using scales other than A and D, in order to meet more specific needs depending on the properties of the material being tested. These two standards guarantee a consistent test method that is suitable for different industrial applications.
Shore hardness table
The Shore hardness scale table presents the different measurement scales to evaluate the rigidity or flexibility of materials. It is divided into several scales, mainly Shore A and Shore D, used depending on the material’s rigidity.
| Shore Scale | Type of Material | Typical Application | Hardness Range |
|---|---|---|---|
| Shore 00 | Very soft rubber, gels | Medical gel, protections | 0 – 100 |
| Shore A | Elastomers, soft rubbers | Tires, O-rings, soles | 0 – 100 |
| Shore D | Hard plastics, rigid rubbers | Polyurethane, rigid plastics | 0 – 100 |
Hardness measurement methods at FILAB
Hardness measurement in accordance with ISO standards 48-4 and 48-9
our other mechanical analysis services
FAQ
The Shore A hardness scale is used to measure softer materials such as rubbers, while the Shore D scale is intended for harder materials such as rigid plastics. There is no direct correspondence between the two scales, as they measure different properties, but it is possible to estimate approximate equivalences.
Shore hardness and Poisson's ratio are different but complementary mechanical properties. Shore hardness measures resistance to penetration (stiffness/softness), while Poisson's ratio describes the relationship between lateral and longitudinal deformation under stress. Although there is no direct link between them, for elastic materials such as rubbers, a low Shore hardness may correspond to a high Poisson's ratio, indicating greater deformability.
The Shore hardness scale to use depends on how stiff or soft the material is. For very soft materials such as gels or foams, use the Shore 00 scale. For elastomers, rubbers and softer materials, use the Shore A scale. Finally, for more rigid materials such as hard plastics, use the Shore D scale. Choosing the right scale ensures accurate measurements that are tailored to your material's specifications.
Shore hardness tests are reliable when carried out under standardised conditions in accordance with recognised standards such as ISO 48-4. These tests are sufficiently accurate to guarantee the quality of materials, ensuring that they meet the mechanical specifications required for optimum performance in industrial applications.
