International Standards Micro IRHD Hardness:
ASTM D 1415 - DIN ISO 48-2 - ISO 48-1 - ISO 48-2 - JIS K 6253-1 - JIS K 6253-2 - VDA 675 101 - a.o.
For the measurement of Micro IRHD hardness, 5 modular digital measuring systems for fully automatic hardness testing are available in our laboratory. The method is suitable for measuring small and thin specimens from 1 mm thickness. A laser-controlled positioning device with optical and automatic centering additionally enables precise measurement on curved surfaces, such as O-rings of various diameters and cord thicknesses.
The IRHD (International Rubber Hardness Degree) hardness test is a test method for determining the ball indentation hardness of elastomers and thermoplastic elastomers. A ball is pressed onto the specimen surface with a defined force. The penetration depth of the ball is measured, and the degree of hardness is calculated accordingly. IRHD hardness testing is divided into different methods, each of which differs in the diameter of the penetrating ball and the penetration force.
Method M (micro hardness testing) is the method with the smallest ball and the lowest force and is therefore particularly suitable for thin and small specimens. It is often used in O-ring testing and finished part testing in general.
Due to various surface effects in the elastomer and a possible slight roughness of the surface (e.g. caused by grinding), the Micro hardness test (Method M) can lead to deviating results compared to the Standard test (Method N). Surface changes, caused e.g. by chemical aging, can also be responsible for different results depending on the method used.