Wheel hardness is based on the material and durometer needed. See the chart and details below to see the comparison.
| Tread Material | Durometer | Scale |
|---|---|---|
| Soft Tread Rubber | 70–80 | A |
| Hard Tread Rubber | 75–85 | D |
| Phenolic | 145–150 | R |
| Polyurethane | 90–95 | A |
| 80A Polyurethane | 80–85 | A |
| 70 D.H.L. Polyurethane | 70 | D |
| Rubber | 70–80 | A |
| Gray Rubber | 70–80 | A |
| Semi-Hard Pneumatic | 90–100 | A |
| Neoprene | 65–75 | A |
| Pneumatic | 55-60 | A |