Edge distance in hardness testing
Edge distance is the minimum required distance from an indentation to the workpiece edge or to another indentation. Too small a distance can cause the material to yield sideways and falsify hardness readings.
Physical-Chemical Mechanism of Action
The edge distance affects local stress states in the workpiece. Too small a distance can cause lateral material flow, which distorts mechanical load capacity and hardness readings.
Metallurgical Relevance & Welding Risks
Too small an edge distance increases the risk of lateral material flow. This can lead to inaccurate hardness readings and impair mechanical strength. Additionally, it can cause damage to the workpiece edge or deformation.
Workshop Practice & Action Instructions
Ensure the edge distance is at least 2 mm. Regularly check the positioning of test indentations and watch for any lateral material flow. If necessary, use additional support or deformation aids to maintain the edge distance.