Home » Quality Control Troubleshooting Guide » Thread Rollers

• Regular Periodic Breaking of the Threads On Dies:
  1. Dies may be out-of-match.
• Top Edge Chipping:
  1. Die Relief may not be deep enough.
  2. There may be too much Taper in the Die adjustment.
• Breaking of the Threads on the FINISH END of the Thread Dies:
  1. The Die Point Angle may too narrow on the blanks.
• Unusual Wear of the START END of the Thread Dies:
  1. Start End Squeeze may be excessive.
• Material Build-up on the Thread Dies:
  1. Coolant may not be sufficient on the Dies.
  2. Redirect Coolant flow.
  3. Check for clogged or broken Coolant Lines.

1. Dies may be out-of-match.
2. Dies may be overloaded. Reduce the Die Squeeze.
3. Look for tipping of the blanks at the Start End. If found, adjust Starter Finger air assist, or increase Hold-Down finger pressure.
4. Check to see if additional grinding of the Starter Finger is required to fit a Shoulder on the blanks.
5. 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.
6. If the dies have a deep Corrugation, consider using dies with shallow or no corrugation.
7. Make sure the Dies are correctly seated in the Die Pockets. If not, the helix angle can be effected causing flakes.
8. Be sure the machine and die set are not too large for the blank size.
9. Check the material hardness and brittleness of the blanks.
10. Make sure there are not seams on the blanks which are creating flakes.

1. Dies may be out-of-match.
2. Dies may have too many shims under dies. Remove and replace with a single plate.
3. Blanks may be tipping at the Start End. Adjust the air assists, increase Hold-Down finger pressure or grind additional clearance to fit any shoulders on the Starter Finger.
4. Check for slipping of the blanks at the Start End. Replace worn dies. If not worn, increase start end squeeze or use Corrugated dies.
5. Be sure the Die Relief surface is smooth and does not have an uneven surface.
6. Make sure the Dies are correctly seated in the Die Pockets. If not, the helix angle can be affected causing drunken threads.
7. Check the dies for the accuracy of their thread form and replace as required.

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.

1. Machine speed may be too high.
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 be sure that only one blank at a time is in the dies.

1. Dies may be overloaded requiring decreasing the Die Squeeze.
2. The dies may be too small.

1. If one side is under-filled, check to be sure the Die Squeeze is not too high.
2. Look for tipping of the blanks at the Start End. If found, adjust Starter Finger air assist, or increase Hold-Down finger pressure.

Key: PD = Pitch Diameter, MD = Major Diameter, ok = Correct, + = Oversize, - = Undersize

1. PD+, MD+ : Blank body may be too large.
2. PD+, MDok : If sharp crests appear, blank body may be too large or thread forms too shallow.
3. PDok, MD+ : Blank body may be too large or thread forms too deep.
4. PDok, MD+ : Blank body may be too small.
5. PD-, MDok : Blank body may be too small or die forms tool deep.
6. PDok, MD- : If crests are sharp or burnished, blank body may be too small or die forms tool shallow.
7. PD+, MD- : Insufficient die squeeze.
8. PD-, MD+ : Overloading of the Dies may be occurring.

1. Check for excessive Finish End die squeeze.
2. Be sure blanks are not out-of-round.
3. Check the hardness and brittleness of the material.
4. Die length may be too short.

Key: PD = Pitch Diameter, MD = Major Diameter

1. If PD and MD are tapered in same direction, blanks may be tapered or Die Set may have shims to create taper.
2. If PD straight but MD tapered, blanks may be tapered or Die Set may not have correct taper.
3. If PD and MD tapered in opposite directions, dies may have a taper at the end with the smaller MD and larger PD.

1. Start End squeeze is excessive.
2. Oversized or deformed blanks.
3. More than one blank at a time being inserted between dies.
4. The machine may not be large enough to handle the blank size.

1. Insufficient vibration on rails.
2. Feed rail too close together.
3. Rail Cover too tight.
4. Oversized or deformed blanks.
5. Inside of Feed Rails are dirty or sticky.