1. Dies may be out-of-match.
2. If blanks are slipping at the Start End, decrease Start End Squeeze or look for worn dies that should be replaced. Consider using dies with Start End Corrugation.
3. Check to see if material has accumulated in the Die thread forms. Clean as required.
4. Check to see if the corrugation is too deep on the thread dies.
5. Check the banks for excessive brittleness or hardness.
6. Look for uneven or pitted surfaces on the Thread Forms on the dies.