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.

Slivers or Flakes on Threads

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

Drunken Threads

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

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

Out-of-round Thread

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

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

Split Thread-axially

Problem Solution
Seamy stock Change stock
Mark from shave tool or hollow mill Regrind tooling

Crests Not Filled Out

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.

Scuffed Crests

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

Hollow Work, Hole Enlarged

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

Hollow Work, Out of Round

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.

Hollow Work, Tapered Threads

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.