Thanks for checking out this reference guide. The Durometer Shoe Hardness scale covers the hardness of material using the Rockwell hardness test or the Durometer test
Using this scale can help you quickly identify the resistance of a material to indentation.
The higher the number, the harder the rubber
How It’s Measured
A durometer is used to measure the rubber hardness. A tester will hold the rubber on a level plan, and press the durometer needle onto the rubber’s surface to measure Shore hardness.
The SI unit of hardness is expressed as N/mm².
Shore hardness scale includes:
- Rigid plastics
- Supersoft gel
Shore 00 Hardness
Shore 00 hardness typically are:
Gels, Sponges, foam, and other very soft rubbers
Shore 0 Hardness
Shore 0 hardness measures soft to medium rubbers and soft plastics
Shore A Hardness
Shore A hardness shows the material’s ability to resist indentation, especially for the softer elastomers (30 – 80)
|Shore A Range||App|
|20 – 35||Rubber band|
|60||Car window wiper|
|70 – 80||Leather belt|
|70 – 90||Hydraulic O rings|
Shore B Hardness
Shore B hardness measures mid-range rubbers and plastics
Shore C Hardness
Shore C hardness measures medium rubbers up to hard plastics
Shore D Hardness
Shore D measures harder elastomer (95 and above)
|50 Shore D||Solid truck tires|
|75 Shore D||Hard hat (typically HDPE)|
|80 Shore D||Cast urethane plastic|
|60 Shore D||Golf balls|
|80 Shore D||Paper-making rolls|
Shore B Hardness
Shore Durometer Hardness Conversions
Quick Reference For Shore A Hardness Level
Here are some quick references for shore A hardness scale when you see something like 10A, 40A, 70A…etc
10A – Extremely soft and can wear out very quickly
20A – Similar to rubber band
40A – Flexible and has hardness level of a pencil eraser
70A – Able to withstand pressure and often used as seals
90A – Lasts longer to withstand pressure and extrusion
Some materials will overlap on the scale.
How Does Shore Hardness Relates To Other Material Properties?
Shore hardness rating is also an indication of the material’s stiffness called flexural modulus. It’s the measures the material’s resistance to bending, while the shore hardness measures resistance to indentation.
What’s The Hardness Of TPE?
TPE material varies based on its recipes. TPE’s hardness range from 10 Shore 00 all the way up to 72 Shore D.