• Rolls are not synchronized.
• Attachment not square with the spindle.
• Loose or worn cross slide.
• Seams in bar stock.
• feed rate too slow causing attachment to walk.
• Incorrect roll diameter

• Rolls are not Synchronized.
• Center of roll is not parallel with the Center of the spindle.
• Loose or worn cross slide.
• Overfilling the roll.
• Seams in bar stock.
• feed too slow.
• Incorrect roll diameter.

• Rolls are not synchronized.
• Center of the Rolls are not Parallel with the center of the spindle
• Part bending while rolling.
• Incorrect thread rolls.

• Center of the roll is not parallel with the center of the spindle.
• Part bending while rolling.
• Incorrect thread roll.

1. P.D. & O.D. both over size.
   • Over size blank diameter.
2. P.D. over size & O.D. under size.
   • Gap between rolls too large, close opening.
3. P.D. correct & O.D. over size.
   • Blank too large.
4. P.D. correct & O.D. under size.
   • Blank too small.
5. P.D. under size & O.D. correct.
   • Roll gap too small.
6. P.D. & O.D. both under size.
   • Blank too small and gap between rolls too small.

1. P.D. & O.D. both over size.
   • Over size blank.
2. P.D. over size & O.D. under size.
   • Move roll closer to center.
3. P.D. correct & O.D. over size.
   • Blank diameter too large
4. P.D. correct & O.D. under size.
   • Blank diameter too small
5. P.D. under size & O.D. correct.
   • Move roll back from the center.
6. P.D. & O.D. both under size.
   • Blank too small and too close to the center.

• If the number of threads on the part is less than 7, then the thread length must be adjusted so that the number of threads is 1/2 a pitch off from a whole number of threads. Such as: 3.5, 4.5, 5.5.

• If the number of threads on the part is less than 7, then the thread length must be adjusted so that the number of threads is 1/2 a pitch off from a whole number of threads. Such as: 3.5, 4.5, 5.5.

1. P.D. Straight & O.D. Tapered
   • Blank O.D. is tapered.
   • Large hole under thread.
2. P.D. & O.D. Tapered in opposite direction.
   • Adjustable thread roll improperly set.

1. P.D. Straight & O.D. Tapered
   • Blank O.D. is tapered.
   • Large hole under thread.
2. P.D. & O.D. Tapered in opposite direction.
   • Attachment not square.

• Some materials stretch when roll formed. Stainless frequently stretches, special rolls are needed.

• Some materials stretch when roll formed. Stainless frequently stretches, special rolls are needed.

• Blank bending while rolling.
• Rolls are not Synchronized.
• Feed too slow, too many revolutions on part.
• Attachment out of square with spindle.

• Blank bending while rolling.
• Feed too slow.
• Restriction of lateral roll float.
• Center of Roll is not Parallel with the center of the spindle.

• Blank bending while rolling.
• Variation over width of blank.
• Large hole under rolling surface.
• Attachment out of square with slide.
• Center of the Rolls are not Parallel with the center of the spindle.

• Blank bending while rolling.
• Blank is not straight.
• Attachment out of square with spindle.
• Hole collapsing, finish hole after rolling.

• Material has seams or laps.

• Material has seams or laps.

• Over filling rolling dies.
• Chips from other tooling getting between thread rolls and blank.
• Rolls are chipped or broken.
• Rolls are not synchronized.

• Over filling rolling die.
• Chips from other tooling getting between thread rolls and blank.
• Rolls are chipped or broken.

• Blank is too small.

*(Many users do not consider this a serious objection and by allowing their threads’ crest to not fill out, over filling is eliminated and roll life is prolonged.)

• Blank is too small.

*(Many users do not consider this a serious objection and by allowing their threads’ crest to not fill out, over filling is eliminated and roll life is prolonged.)

• Return cam worn (Not retracting fast enough).
• Rolls and/or gear train is binding.
• Rolls are going past center.
• Rolls are the wrong diameter.

• Return is not fast enough.
• Roll is on part too long.
• Roll or blank is wrong diameter.

1. Hole closes in.
   • Finish hole after rolling.
   • Feed may be too fast.
2. Hole enlarges.
   • Do not roll while drilling.
   • Finish hole after rolling.
3. Tapered threads(Due to uneven wall thickness or support from adjacent section).
   • Finish hole after rolling.
   • Re-adjust taper in the adjustable roll.

1. Hole closes in.
   • Finish hole after rolling.
   • Feed may be too fast.
2. Hole enlarges.
   • Do not roll while drilling.
   • Finish hole after rolling.
3. Tapered threads(Due to uneven wall thickness or support from adjacent section).
   • Finish hole after rolling.
   • Re-adjust taper in the attachment.