Draw-bead Test on Steel Sheets

This test is designed to determine the coefficients of friction between steel sheet and cup deep drawing tool. The ideal lubricant for the deep drawing process can then be established, enabling cracks and creases to be avoided and optimizing the forming process. The draw-bead unit can easily be installed in a standard testing machine.

For the test a sheet metal strip with typical dimensions 300 mm x 30 mm x 2 mm is gripped axially in the upper specimen
grips and the draw-bead tool closed; the sheet metal strip is then pulled through the draw-bead tool. This procedure can be repeated automatically, the number of repeats being varied as required. Digital control of the draw-bead tool clamping force guarantees reliable, reproducible measured values, while the tool die can quickly be changed to cover different testing specifications.