What is the hardness of rubber?

The hardness of rubber refers to the resistance of vulcanized rubber to the pressure of probe of rigid measuring instrument under given conditions. Shore hardness is the degree to which the blunt needle falls into the depression of the specimen surface when the specimen is pressed by the blunt needle of the measuring instrument, and is expressed by the degree (or reading) indicated by the pointer of the measuring instrument. The International hardness of rubber is the difference in the depth of the rubber pressed under certain conditions, using a specific presser (measuring the steel ball) under the action of a small contact pressure and a large total pressure. Rubber International hardness (IRHD) is based on this difference, using the "pressed depth difference D and the rubber international hardness of the relationship table (the following table or according to the table made of the curve, or by the rubber international hardness of the dial to read directly. Table: pressed depth difference D and rubber international hardness value of the relationship table