Art HedrickAvoiding the 7 Deadly Sins of Stamping: Part 3 Poor Die Setup
June 6, 2024Comments
In a stamping operation, most damage to the dies takes place during the die-setup process. This especially is true for progressive dies. Often, half-cuts and forms are made during the strip-threading process. As a result, severely unbalanced loads occur in the tool. This in turn, may cause tooling sections to misalign and shear.
During the die-threading process, startup scrap is generated and, if left in the die, may double-feed sheet metal into the tool. Often during setup, pressure, stripper and draw pads are half-loaded and unbalanced. The list goes on and on.
Establishing a good die-setup procedure, or “recipe,” is critical to the success of any metal stamping company. In this two-part article, I will focus on several items to consider when setting up progressive dies.
Clean, Clean, Clean
Progressive, line and transfer dies often are manufactured to tolerances of less than 0.0005 in. For the die to function properly, and for tooling components to interface with the proper clearance, the top and bottom of the die must be clean and free from any debris such as dirt, slugs, grease and oil. In addition, the bolster plate and ram must be cleaned. If using a rolling bolster (typically for larger dies), clean the bottom surface of the bolster and the press bed, or frame. It’s a good idea to run a flat file along the bottom and top of the die, to remove any high spots that may have resulted from previous improper, dirty die setups (Fig. 1).
For progressive dies, ensure that the centerline of the die’s pilots run parallel to the coil-feed direction. Also ensure that you align the coil edge with the die’s side rail. If these items are set up incorrectly, you may not be able to feed the die smoothly (Fig. 2).
Before lowering the press ram, make sure that the shut height is slightly greater than the thickness or the final shut height of the tool. Don’t set the press’s shut height to the die’s final or finished shut height. Numerous computer-operated press systems will automatically set the press’s final shut height. However, keep in mind that a die’s finished shut height is calibrated with the die fully loaded with sheet metal.
With the die nearly closed and all guide pins fully engaged, fasten all bolts and clamps. This process often is referred to as “floating the die in.” 
