Shore hardness is the hardness of an O-ring.
In the field of elastomers (NBR, EPDM, FKM, etc.), the Shore hardness can be between 5 and 100 Shore. However, only the 40 to 90 Shore range is of interest for the manufacture of O-rings.
Note: The tolerance specification for Shore hardness is ± 5 Shore.
Each O-ring material has a standard hardness. We have put together a short table to give you a quick overview of all the important O-ring materials: