The fin pass forms the weld V and holds the edges together at the point where the high frequency current runs. Accuracy here is what decides whether the seam is sound.
Why it matters on the line
- Sets the weld V angle and the edge contact, which decides the high frequency current path and therefore the weld quality
- The edge of the roll is the part that wears; we grind the V and check the edge radius before shipping
- Matched to the seam guide, because a fin roll and a seam guide that disagree will produce a wandering weld
- Supplied as a single roll, a pair, or as part of a full pass line set with the matching stands
What we supply
| Item | What we hold to | Why it matters |
|---|---|---|
| V angle | As your pass line drawing | Sets the weld V and the current path |
| Edge radius | Ground to drawing | A sharp edge burns and a soft edge leaks |
| Hardness | HRC 58–62 | The edge is the wear point |
| Matching | Paired with your seam guide and weld box | Alignment is part of the product |
Every item is machined in our own workshop and marked before it is packed, so it goes back to the stand it came from. If you send us a drawing or a sample we work to that; if you are not sure what you need, send us the mill model and the pass line and we will tell you.
Related products
Tube mill rolls · Tube mill roll set · Tube mill roll design · ERW tube mill line
Send us the drawing or the sample
A drawing, a photo with a ruler in frame, or the mill model is enough for us to quote and to tell you honestly whether the item should be reground or replaced.
