4. Friction tests

These tests are carried out to achieve two objectives, which are not contradictory, but are significantly different:

• to measure the ability of a sheet metal to successfully undergo a given forming operation, or the ability of a lubricant or tool surface treatment to solve a given friction, transfer or wear problem, etc. The type of test and its implementation are therefore chosen according to their selective nature. The Inland test is a very good example of such an approach for a sheet metal formability problem, where its friction properties on the blank holder are decisive. The plane/plane friction test with increasing normal force is a good example of a lubricant discrimination test. Another example of a particularly severe formability test is the sheet-metal pass-through test;

• or to build up a tribological data bank...