Thread Roll Troubleshooting

Thread Filled Out In Center, But Not Towards Ends, Or Vice Versa

1. Roll with varying diameter from end to end, or
2. Blank with varying diameter from end to end.

Split Thread – Axially

1. Seamy stock, or
2. Mark from shave tool or hollow mill

Poor Finish On Thread

1. Correspondingly poor finish on rolls, or
2. Rolls that are worn out or broken, or
3. Overfilling rolls, or
4. Rolls not in match, or
5. Material accumulated in threads on roll, or
6. Material not ductile enough for cold-working

Scuffed Crests

1. Attachment not retracting fast enough, or
2. Rolls and gear train binding, or
3. Rolling beyond center line of work, or
4. Material accumulated in threads on rolls

Hollow Work, Hole Closes In

1. Machine hole after rolling, or
2. Needs supporting mandrel, or
3. Feed rate too high, causing too rapid penetration

Hollow Work, Hole Enlarged

1. Machine hole after rolling, or
2. Supporting mandrel too tight, or
3. Blank too large on major diameter, or
4. Feed rate too high causing too rapid penetration

Hollow Work, Out Of Round

1. Machine hole after rolling, or
2. Feed rate too high causing too rapid penetration, or
3. Too few work revolutions