Leeb rebound hardness test
A dynamic hardness testing method that evaluates the velocity loss of an impact body before and after striking the metal surface. It is primarily used for rapid and portable component testing.
The Leeb method is a dynamic hardness testing method. A small impact body with a carbide ball is shot onto the surface with a defined spring force and bounces back. The hardness value is calculated from the ratio of impact to rebound velocity. For weld testing, it's only of limited use because it measures surface hardness. If you test hardness in the transition area to the heat-affected zone, you can roughly tell whether the structure has become too hard or too soft. It's a quick comparative test, not a substitute for proper hardness testing in the lab. Make sure the surface is clean and smooth, otherwise it will distort the rebound. And the test location should not be too thin, otherwise the body will penetrate and you'll measure the anvil instead of the workpiece.