Limiting Drawing Ratio (LDR) Test / Swift Deep Drawing Cup Test

The Swift deep drawing cup test is a method used for the determination of sheet metal forming properties. The test is also referred to as limiting drawing ratio test or LDR test.

The limiting drawing ratio (LDR) test evaluates the deep drawability of sheet metals. It indicates the maximum ratio of circular blanks to the diameter of the die, by deep drawing the blank into a cup, without crack formation.