What is Durometer?

Real world durometer examples
Real world shore A durometer examples

Durometer is a measure of how hard a material is. Technically, it’s a measure of how hard it is to permanently indent a material. There are actually 12 different durometer scales each measured from 0 (softest) to 100 (hardest), but for the we’ll mainly be talking about Shore A since it’s the most common in fluid sealing applications.

How is Durometer Measured?

Measuring durometer is fairly simple. You put a standard metal rod at a standard pressure on to a material for 15 seconds, then you measure the depth of the indentation. For example, in Shore A durometer testing, 1.1 to 1.4 mm diameter steel rod with is applied with .822 Kg of mass (1.81 lb) on a sheet of rubber for 15 seconds.

Which Durometer is right for your Project?

Property Low Durometer High Durometer
Durability Less Durable
More easily marked
More Durable
Harder to mark
Compressibility More Compressible Less Compressible
Flexibility More Flexible
Better for curved surfaces
Less Flexible