Hardness of Rubber Durometer
The Durometer is the International Standard Instrument used to measure the hardness of rubber or rubber-like materials. Durometers measure hardness by the penetration of an indentor into the rubber sample. The calibrated reading is expressed in a number value. The hardness values are always expressed in terms of plus or minus (±) five points (example: 60±5 Durometer).
It is important to note that when testing hardness of a rubber sample, the material should not be less than ¼” thick (.250″).
| Durometer Type (Shore) | Applicable to these types of materials |
|---|---|
| Type A (Shore) | Soft rubber & plastics |
| Type D (Shore) | Type D (Shore) |
| Type 00 (Shore) | Sponge & foam |
Approximate Durometer Hardness Comparisons
| Shore A | Shore D | Shore 00 |
|---|---|---|
| 100 | 58 | – |
| 95 | 46 | – |
| 90 | 39 | – |
| 85 | 33 | – |
| 80 | 29 | 98 |
| 75 | 25 | 97 |
| 70 | 22 | 95 |
| 65 | 19 | 94 |
| 60 | 16 | 93 |
| 55 | 14 | 91 |
| 50 | 12 | 90 |
| 45 | 10 | 88 |
| 40 | 8 | 86 |
| 35 | 7 | 83 |
| 30 | 6 | 80 |
| 25 | – | 76 |
| 20 | – | 70 |
| 15 | – | 62 |
| 10 | – | 55 |
| 5 | – | 45 |
The above values are approximate and are not to be used as an exact equivalent. This information is provided as a selection guide only.