Density Measurement Charts for Materials

Density Ranges of Various Materials

MaterialDensity Range (kg/m³)
Ceramics1800 - 12000
Porous ceramics1100 - 3300
Glasses2200 - 4000
Metals and alloys1700 - 22000
Composites1200 - 2000
Woods and wood products<300 - 1200
Polymers800 - 2400
Rubbers900 - 2300
Polymer foams30 - 500

Density Range Chart

Different Scales for Measuring Hardness

1. Mohs Scale of Hardness

Description: Developed by Friedrich Mohs, this scale ranks minerals based on their ability to scratch another mineral. It is ordinal and ranges from 1 (talc) to 10 (diamond).

Applications: Mainly used in geology and mineralogy.

Scale:

  • Talc (1)
  • Gypsum (2)
  • Calcite (3)
  • Fluorite (4)
  • Apatite (5)
  • Orthoclase (6)
  • Quartz (7)
  • Topaz (8)
  • Corundum (9)
  • Diamond (10)


2. Brinell Hardness Test

Description: Measures the indentation hardness of materials through the scale of penetration of an indenter, typically a hard steel or carbide ball.

Applications: Suitable for metals and alloys with coarse or uneven grain structures.

Procedure: A load is applied on the indenter for a specified time, and the diameter of the indentation left on the material is measured.

Scale: Expressed in Brinell Hardness Number (BHN or HB).


3. Rockwell Hardness Test

Description: Measures the depth of penetration of an indenter under a large load compared to the penetration made by a preload.

Applications: Used for testing metals, particularly steel and other hard alloys.

Procedure: The Rockwell test involves applying a minor load followed by a major load and then measuring the depth of the indentation.

Scale: Various scales (A, B, C, etc.) based on different indenter types (diamond, steel ball) and loads. For example, Rockwell C (HRC) is commonly used for harder materials.


4. Vickers Hardness Test

Description: Uses a diamond pyramid indenter and measures the diagonal length of the indentation made by a specified load.

Applications: Suitable for all metals and has one of the widest scales among hardness tests.

Procedure: A load is applied for a specific time, and the indentation's diagonals are measured.

Scale: Expressed in Vickers Pyramid Number (HV or VHN).


5. Knoop Hardness Test

Description: Similar to the Vickers test but uses an elongated diamond indenter, making it more suitable for brittle materials and thin sheets.

Applications: Often used for ceramics, thin layers, and coatings.

Procedure: A load is applied, and the indentation's long diagonal is measured.

Scale: Expressed in Knoop Hardness Number (KHN).


6. Shore Hardness

Description: Measures the resistance of a material to indentation using a spring-loaded indenter.

Applications: Commonly used for polymers, elastomers, and rubbers.

Scale: Different scales (Shore A, Shore D) based on the material being tested. Shore A is for softer materials, while Shore D is for harder ones.


7. Leeb Rebound Hardness Test

Description: Measures the rebound of a standardised impact body from the material.

Applications: Suitable for large and heavy workpieces.

Procedure: An impact device is used to hit the material, and the rebound velocity is measured.

Scale: Expressed in Leeb Hardness Number (HL).


8. Janka Hardness Test

Description: Measures the resistance of wood to denting and wear.

Applications: Used primarily for wood.

Procedure: A steel ball is pressed into the wood until half the ball's diameter is embedded.

Scale: Expressed in pounds-force (lbf).

Difference Between Hardness and Density

Hardness

Definition: Hardness is a measure of a material's resistance to deformation, typically by indentation, scratching, or abrasion. It reflects how a material can withstand mechanical wear and penetration.

Measurement: Hardness is measured using various scales and tests, each suited for different types of materials and applications. Common tests include:

  • Mohs Scale: Measures scratch resistance.
  • Brinell Hardness Test: Measures indentation hardness using a steel or carbide ball.
  • Rockwell Hardness Test: Measures the depth of penetration of an indenter.
  • Vickers Hardness Test: Uses a diamond pyramid indenter to measure indentation.
  • Shore Hardness: Measures resistance to indentation, often used for polymers and rubbers.

Applications: Hardness is critical in applications where materials must resist wear, scratching, or penetration, such as in cutting tools, construction materials, and coatings.


Density

Definition: Density is the measure of mass per unit volume of a material. It reflects how much matter is packed into a given space.

Measurement: Density is calculated using the formula:

Density = Mass / Volume

The mass is measured using a balance, and the volume can be determined through geometric calculations for regular shapes or water displacement for irregular objects.

Units: Density is commonly expressed in kilograms per cubic meter (kg/m³) or grams per cubic centimeter (g/cm³).

Applications: Density is important in fields such as material science, engineering, and physics, where the mass-to-volume ratio impacts buoyancy, strength, and structural integrity.

Key Differences

  • Nature:
    • Hardness: Relates to a material's ability to resist deformation.
    • Density: Relates to the amount of mass in a given volume of material.
  • Measurement Methods:
    • Hardness: Measured using specific tests (Mohs, Brinell, Rockwell, Vickers).
    • Density: Calculated using mass and volume measurements.
  • Units:
    • Hardness: Expressed in units specific to each test (e.g., HRC for Rockwell, HV for Vickers).
    • Density: Expressed in kg/m³ or g/cm³.
  • Applications:
    • Hardness: Important for assessing wear resistance, scratch resistance, and durability.
    • Density: Crucial for understanding material properties like buoyancy, weight, and structural strength.

Summary

While both hardness and density are properties of materials, they describe different characteristics. Hardness focuses on resistance to deformation and surface wear, while density measures how much mass is contained in a given volume. Understanding both properties is essential for selecting the right materials for specific applications and ensuring their optimal performance.


Shore A Scale for Algeos Foam Materials

At Algeos, we offer a range of soft, medium, and firm materials designed to meet the diverse needs of our customers. To accurately measure and classify the hardness of these materials, we utilise the Shore A scale, which is specifically suited for softer, flexible materials like those we provide.

Understanding the Shore A Scale

The Shore A scale measures the hardness of materials that are softer and more flexible, such as rubber, polymers, and foams. The scale ranges from 0 to 100, with lower numbers indicating softer materials and higher numbers indicating harder materials. The test involves pressing a spring-loaded indenter into the material and measuring the depth of the indentation.

Shore A Scale - Why we use it at Algeos

Appropriate for Soft to Medium Hardness Materials:

The Shore A scale is specifically designed for testing the hardness of materials that fall within the soft to medium hardness range. This makes it ideal for Algeos' range of soft, medium, and firm materials.


Precision and Reliability:

The Shore A scale provides precise and reliable measurements, allowing us to consistently classify and compare the hardness of our materials. This ensures that our customers receive products that meet their specific requirements.


Wide Range of Applications:

The Shore A scale is versatile and applicable to a wide range of materials used in various industries, including healthcare, orthotics, prosthetics, and footwear. This makes it a suitable choice for the diverse product offerings at Algeos.


Non-destructive Testing:

The Shore A hardness test is non-destructive, meaning it does not cause permanent damage to the material being tested. This allows us to test and classify materials without compromising their integrity or usability.


Relevance to Product Performance:

The hardness of materials directly impacts their performance in applications such as cushioning, support, and shock absorption. Using the Shore A scale helps us ensure that our materials will perform as expected in their intended applications.


Customer Confidence:

By using a recognised and standardised hardness scale like Shore A, we provide our customers with confidence in the quality and consistency of our materials. They can trust that the products they receive will meet their specifications and perform reliably.

Application Examples at Algeos

Soft Materials:

Our soft materials, which fall on the lower end of the Shore A scale, are ideal for applications requiring high flexibility and cushioning, such as insoles, padding, and protective gear.


Medium Materials:

Materials classified as medium on the Shore A scale offer a balance of flexibility and support, making them suitable for orthotic devices, midsole components, and general cushioning applications.


Firm Materials:

Firm materials, measured at the higher end of the Shore A scale, provide enhanced support and stability. These are commonly used in applications requiring rigidity and durability, such as structural orthotic elements and robust footwear components.

Conclusion

Algeos uses the Shore A scale to measure and classify the hardness of our soft, medium, and firm materials due to its suitability for flexible materials, precision, non-destructive nature, and relevance to product performance. This ensures that we provide high-quality, reliable products that meet the diverse needs of our customers. By leveraging the Shore A scale, we uphold our commitment to delivering excellence in all our material offerings.