Minimum Spacing
Minimum spacing is the necessary distance between hardness test indentations to avoid work-hardening effects and ensure measurement accuracy.
Physico-chemical mechanism of action
Hardening is a phenomenon where the material transitions to a harder structure through rapid cooling. If hardening points are too close together, they influence each other and lead to inaccurate measurement values.
Metallurgical relevance & risks in welding
A minimum distance that is too small can lead to incorrect hardness measurements. This can result in the material not achieving the required hardness level or being over-hardened, which can cause cracks and other defects in the component.
Workshop practice & instructions
Make sure that the minimum distance between hardening points is at least 2 mm. For special materials or high hardness values, this value can be higher. Always follow the manufacturer's recommendations.