Formability Criteria for Selecting Sheet Metal Lubricants

The proliferation of new coated steels, primarily zinc-based, has highlighted the need for understanding the interactions among the components of the forming system - part design, die design, material, lubrication, and press. Specialized laboratory tests have recently emerged to duplicate and measure quantitatively the sum of these interactions as a function of different lubrication conditions. The coefficients of friction derived from the DBS (Draw Beam Simulator) and the DF (Dome Friction) tests are used in this paper to document a number of system interactions. The results from these simulative friction tests are confirmed by experiments conducted on a highly instrumented, laboratory controlled, test pan die. The conclusion is reached that press shop needs are best met by use of a single lubricant which is insensitive to other components of the forming system.