Erichsentest

Erichsentest, also known as the Erichsen cupping test, is a material formability test used to assess the ductility of sheet metals. It provides a simple, semi-quantitative measure of how readily a metal can undergo plastic deformation before cracking.

During the test, a circular sheet sample is clamped over a circular die opening. A hemispherical punch is driven into the sheet at a controlled rate, forming a cup-shaped indentation. The test is stopped when a crack forms or at a predefined maximum depth. The cup depth, measured in millimeters, serves as the primary index of ductility; higher values indicate greater formability.

Values depend on material, temper, thickness, and lubrication. The Erichsen test is widely used for steel, copper, aluminum, and other metals, often as part of supplier qualification or process development. It is particularly useful for comparing alloys and heat-treat conditions and for quick screening on production floors.

Standards and procedures for the test exist in various regions, and methods can vary slightly. The test is simple but sensitive to setup, clamping, edge quality, and friction at the tooling, which can influence results. It is typically used as a screening tool rather than a definitive predictor of deep-drawing performance for complex parts.

Related formability assessments include other cupping tests and bend/forming limit tests. The test’s exact inventor is not consistently cited in modern references, and the method has been refined over decades to suit different materials and industry needs.