Slitting Lines for Pipe & Tube Manufacturing
In an ERW tube mill, weld quality is decided before the strip reaches the mill: skelp width variation becomes seam gap variation, and edge burr becomes weld defects. The slitting line is effectively the first station of the tube mill.
Friend Engineering Works supplies slitting lines to pipe and tube manufacturers producing everything from 15mm conduit to large structural hollow sections. Our lines hold ±0.1mm width tolerance with clean edges, so your mill runs stable seams at speed.
Why Tube Mills Are the Toughest Slitting Customers
- Width tolerance is weld geometry: skelp width directly sets the material available at the weld point — variation shows up as seam gap or excessive squeeze-out
- Edge condition matters: burrs and edge camber cause weld spatter, scarfing problems and inclusions
- Camber ruins straightness: strip camber from uneven slitting tension becomes tube bow
- Volume duty: tube mills consume strip continuously — the slitting line must keep multiple mills fed
Recommended Configuration for Tube Mills
| Parameter | Tube Mill Duty |
|---|---|
| Material | HR skelp 1.5–10mm, CR/GI 0.8–3mm for precision tubes |
| Width tolerance | ±0.1mm |
| Coil weight | Up to 40 tonnes (jumbo mill coils) |
| Tension system | Individual strip tension for camber-free skelp |
| Recoiler | Separator discs and provisions for mill-ready coil packaging |
SS and Precision Tube Applications
Stainless steel tube producers (furniture, dairy, automotive exhaust) need the SS-specific configuration — surface protection and interleaving — combined with tube-grade width control. See our stainless steel processing page for that configuration.
Recommended Equipment
- Slitting Line — Friend Engineering Works slitting lines are designed to ensure the highest standards of quality and productivity while processing different materials.
- Decoiler Machine — Our decoiler machines are designed for efficient and safe uncoiling operations with heavy-duty construction.
- Recoiler Machine — Our recoiler machines provide consistent tension control for rewinding processed metal strips.
Frequently Asked Questions
What width tolerance does ERW tube making require from slit strip?
Most ERW mills specify ±0.1mm to ±0.2mm on skelp width depending on tube size and standard. Our slitting lines hold ±0.1mm, which keeps seam geometry stable and scarfing consistent across the coil.
Can one slitting line feed multiple tube mills?
Yes — that is the standard arrangement. A single slitting line typically produces skelp for several mills, with the recoiler producing separator-packed multi-strip coils. Line capacity is sized from your mills' combined consumption, not from a single mill's speed.
Why does my tube bow even though the mill is set correctly?
Persistent tube bow often traces back to strip camber from the slitting operation — uneven tension across strips or a worn slitter setup. A line with individual strip tension control and a properly maintained head produces camber-free skelp; we can also assess your existing line through our service division.