Hardness of rubber

Most rubber materials fall under the Shore A durometer (hardness) scale. Rubber harder than 100A is measured on the Shore D scale.

Examples range from soft to hard…

• Rubber Band: Shore hardness 20A 
• Pencil Eraser: Shore hardness 40A 
• Car Tire Tread: Shore hardness 60A 
• O Ring: Shore hardness 70A 
• Marine Fenders: Shore hardness 75A 
• Shopping Cart Wheel: Shore hardness 100A 
• Bowling Ball: Shore hardness 72D

(Source: GB Rubber Supply Ltd. - Products & Materials)