Troubleshooting

Troubleshooting Common Threading Problems that Can Occur

CJWinter has identified and solved thread rolling problems of all types over its 60+ year course.

From slivers and flakes to scuffed crests, you can find the solution to your thread rolling issue here. Click on your problem below to learn more about its cause and solution. Can’t find the information you’re looking for? Our team is more than happy to help — contact us today.

Problem
Solution
Rolls not in match
Resynchronize rolls
Center line of rolls not parallel with center line of work
Check slide for alignment
Loose or worn cross slide or adapter
Check slide gib and springs. Tighten adapter if used.
Overfilling rolls
Reduce blank diameter
Material not adaptable to cold-working
Change material. Check with material supplier.
Rough finish on blank
Regrind tooling
Seamy stock
Not suitable for roll threading
Feed rate too slow, causing rolls to slip on work
Increase rate of penetration
Incorrect roll diameter
Use correct rolls for job
Problem
Solution
Rolls not in match
Resynchronize rolls
Center line of rolls not parallel with center line of work
Check slide for alignment
Inaccurate rolls
Replace rolls
Work bending during rolling.
Support part during rolling operation or slow down penetration rate if possible
Off-Size Threads
Problem
Solution
Pitch diameter and major diameter, both oversize
Oversize blanks
Reduce blank diameter
Pitch diameter oversize, major diameter correct
Oversize blanks. If finished thread is full, thread on roll is too shallow.
Use correct rolls for job
Pitch diameter oversize, major diameter undersize
Insufficient penetration on rolls. If finished thread is full, thread on roll is too shallow.
Increase roll penetration
Pitch diameter correct, major diameter oversize
Blank too large. Thread on roll deeper than necessary.
Reduce blank diameter
Pitch diameter correct size, major diameter undersize
Blank too small. If finished thread is full, thread on roll is too shallow.
Increase blank diameter. Use correct rolls for job
Pitch diameter undersize, major diameter oversize
Excessive penetration. Thread on roll deeper than necessary.
Reduce roll penetration. Use correct rolls for job.
Pitch diameter undersize, major diameter correct size
Blank too small. Thread on roll deeper than necessary.
Increase blank diameter. Use correct rolls for job.
Pitch diameter and major diameter both undersize
Blank too small
Increase blank diameter
Problem
Solution
Out of round blank
Shave tool not reaching center or not cleaning up rough form diameter
Center line of rolls not parallel with center line of work
Check slide for alignment
Feed rate too high
Reduce rate of penetration
Insufficient work revolutions
Reduce rate of penetration
Material not ductile enough for cold-working
Change material. Check with supplier.
Attachment not on center line of work
Reset cross slide with gauge
Tapered Threads
Problem
Solution
Pitch diameter straight. Major diameter tapered and not filled on small end
Tapered blank
Straighten blank
Pitch diameter and major diameter both tapered same way
Tapered blank
Straighten blank
Pitch diameter and major diameter tapered in opposite directions and thread not filled out on end with small major diameter
Rolls not penetrating deep enough on edge with large pitch diameter and small major diameter, or work bending during rolling
Support part during rolling. Part deflecting out of contact with center of rolls.
Thread with expanded lead
Expanded lead in rolls
Use correct rolls
Thread with expanded lead
Material extruding on short length of blank
Use longer blank and remove excess in another position
Thread with contracted lead
Contracted lead in rolls
Use correct rolls for job
Poor thread form
Work bending during rolling
Support part during rolling
Poor thread form
Rolls not in match
Resynchronize rolls
Poor thread form
Too many work revolutions
Increase rate of roll penetration
Poor thread form
Center line of rolls not parallel with center line of work
Check slide for alignment
Thread filled out in center, but not towards ends, or vice versa
Blank with varying diameter from end to end
Check blank for taper or shave tool not reaching center
Thread filled out in center, but not towards ends, or vice versa
Center line of rolls not parallel with center line of work
Check slide for alignment
Poor finish on thread
Overfilling rolls
Check blank diameter oversize.
Poor finish on thread
Rolls not synchronized.
Resynchronize thread rolls.
Poor finish on thread
Material accumulated in threads on roll.
Replace rolls if material cannot be removed.
Poor finish on thread
Material not ductile enough for cold-working.
Change material.
Poor finish on thread
Chips, from other operations, between rolls and work.
Make sure a good jet of clean oil is reaching rolling position
Poor finish on thread
Correspondingly poor finish on rolls.
Replace rolls.
Poor finish on thread
Rolls that are work or broken
Replace rolls
Problem
Solution
Seamy stock
Change stock
Mark from shave tool or hollow mill
Regrind tooling
Problem
Solution
Blank too small
Increase blank diameter
Thread on roll too deep
Replace rolls with rolls of correct depth for job. NOTE: Special truncated rolls are available from Winter.
Problem
Solution
Attachment not retracting fast enough
Increase speed of roll retraction
Rolls and gear train building
Check gear train, remove any foreign matter
Rolling not on center line of work
Reset slide with gauge
Material accumulated in threads on rolls
Check oil jet flowing on rolling position
Insufficient wall thickness
Machine hole later in operation or use smaller drill
Improper supporting mandrel
Use proper supporting mandrel
Feed rate too high, causing too rapid penetration
Slow down penetration rate
Problem
Solution
Material extruding due to insufficient wall thickness.
Use smaller drill before rolling
Supporting mandrel too tight
Reduce mandrel diameter
Blank too large on major diameter
Reduce blank diameter
Feed rate too high causing too rapid penetration.
Slow down rate of penetration
Problem
Solution
Material deforming due to insufficient wall thickness.
Drill later in cycle.
Feed rate too high causing too rapid penetration.
Slow down rate of penetration.
Too few work revolutions.
Slow down rate of penetration.
Problem
Solution
Uneven and insufficient wall thickness.
Drill later in cycle.
Improper mandrel not giving support where needed.
Check mandrel for size with hole.
Feed rate too high causing too rapid penetration.
Slow down rate of penetration.
Taper of rolls not great enough to compensate for tendency of work to taper.
Use correct rolls for job.

If you need further assistance, please call us at 585.429.5000, or use our Contact Page to email a description of your problem. For detailed specification on particular Thread Roll Attachments, that information is available online in the Thread Roll Attachments Page. You can also download our Thread Rolling Solutions brochure to help determine correct working face and roll position.

If you need further assistance, please call us at 585.429.5000, or use our Contact Page to email a description of your problem. For detailed specification on particular Thread Roll Attachments, that information is available online in the Thread Roll Attachments Page. You can also download our Thread Rolling Solutions brochure to help determine correct working face and roll position.
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