In the past, lead measurement was carried out with a surface profiler according to Daimler’s factory standard MBN 31007-7 or the thread method. Thread-like scoring structures that occur, for example, when the dressing helix is transferred from the grinding tool to the machined surface, can be detected in this way. The grooves can cause leaks or dry running of the seal on the shaft.
Lead measurement according to MBN 31007-7 only detects long-wave periodic structures, but not microstructures, which in many cases contribute significantly to the conveying effect of the sealing system. Microstructures have mainly been detected with the thread method up to now. Due to several factors, however, this method cannot be quantified and documented sufficiently, because it is strongly influenced, for example, by the type of thread and the fluid used in the test procedure.