We're responsible for building-----we're responsible for manufacturing-----we're responsible for training
One control system from the coil to the stack: uncoiling, levelling, laser blanking, punching, bending and palletising, with no manual handling in between.
A coil-to-part line takes steel in coil form and returns a finished, formed, stacked component without a person touching the material in between. The chain is uncoiling → levelling → laser blanking or turret punching → automatic bending → stacking, optionally with a robot welding station at the end. Everything runs under one control system with process interlock and data traceability.
It is worth it when three conditions hold together: your product range is reasonably standardised, your volume is continuous rather than campaign-based, and your material sits in the 0.5 to 2.0 mm window. Coil is cheaper per tonne than cut sheet, intelligent nesting from a continuous strip raises material utilisation, and the handling, shearing and work-in-progress between machines disappears. If your mix is high and your batches are small, a punch-and-bend cell fed from sheet is usually the better investment — a coil line rewards repetition, and we will say so before quoting.
STON CNC (Qingdao Ston Mechanical Technology Co., Ltd.) is a Chinese original manufacturer of CNC panel benders and turret punch presses, founded in 2006 in Qingdao, China. All equipment described here is built inside STON CNC's own 20,000㎡ factory, from casting and heat treatment through machining, assembly and inspection. Machines carry ISO 9001 quality certification and CE marking under Machinery Directive 2006/42/EC, and are exported to more than 80 countries. View certifications and patents →
Coil-fed lines suit products built from a limited number of panel types repeated at high volume. Below are the part families we most often configure a line around.
Cut sheet carries a conversion cost per tonne over coil, and every shear operation creates offcut that a continuous strip does not. Combined with intelligent nesting across the strip, material utilisation is where a coil line usually recovers its cost first — and on thin gauge, material is the largest single item in the part cost.
Sheet-based production stacks material at each stage: after shearing, after cutting, after punching, before bending. Each stack is floor space, handling labour, damage risk and cash tied up. Under one control system with process interlock, the part moves from stage to stage without ever being set down.
Coil set and edge wave do not announce themselves until a panel refuses to bend straight or a door face shows a ripple. A precision leveller with 40Cr rollers on self-aligning bearings delivers a flatness of roughly ±1 mm/m² and diagonal accuracy within 1 mm over 2000 mm, so the blank arriving at the bender is already correct.
Lines are modular. Most customers start at the blanking end, where the material saving is, and extend to forming once the blank supply is stable.
These are the figures your building, your electrical contractor and your material buyer need before a layout can be drawn. Bring them to the first engineering call.
| Parameter | Value | Notes |
|---|---|---|
| Raw material | Cold-rolled sheet, galvanised sheet, stainless steel | Aluminium on request |
| Sheet thickness | 0.5–2.0 mm | Stainless typically ≤1.5 mm |
| Coil width | 200–1500 mm (laser line typically 1000–1500 mm) | Confirm against your product range |
| Coil weight | ≤10 T | Determines uncoiler and floor loading |
| Coil inner diameter | φ470–630 mm | Configuration dependent |
| Coil outer diameter | φ1000–1600 mm | — |
| Levelling accuracy | ±1 mm/m² | Decides whether flat faces stay flat |
| Diagonal accuracy | ≤1 mm / 2000 mm | — |
| Threading speed | 5 m/min | Coil changeover |
| Line speed | 0–12 m/min, adjustable | Leveller linear speed |
| Running height | +800 mm | Affects pit and platform design |
| Surface quality | Flat strip, no processing defects introduced | — |
| Power supply | 3φ AC 400 V ±5%, 50 Hz ±2% | Configured to destination |
| Laser 3 kW capacity | ≤50 kVA installed, 60 kVA supply recommended | — |
| Laser 6 kW capacity | ≤100 kVA installed, 120 kVA supply recommended | — |
| Compressed air | 0.5–0.6 MPa, 0.6 m³/min | — |
Standardised panel families in 0.5–2.0 mm, produced continuously, where material cost dominates the part cost and the same sections repeat month after month.
High-mix job-shop work with small batches, thickness above 2.0 mm, panels wider than the coil range, and any product built mainly from roll-formed profiles or deep-drawn shells.
Even with a full line, keep a press brake for specials, prototypes, thick parts and anything outside the coil width. The line handles the repeatable volume; the brake handles everything else.
Risk assessment follows EN ISO 12100; safety-related control functions such as light-curtain interruption and emergency stop are specified to EN ISO 13849-1. Hydraulic press brakes supplied into the EU are built against EN 12622. Machines placed on the EU market carry CE marking under Machinery Directive 2006/42/EC with the accompanying technical file. Quality management is certified to ISO 9001, and machined structural tolerances follow ISO 2768. A line is a single assembly of machinery under the Machinery Directive, so risk assessment to EN ISO 12100 is carried out across the whole line rather than machine by machine, with interlocked guarding and safety functions specified to EN ISO 13849-1. Machined structural tolerances follow ISO 2768.
On the machines this means fully enclosed rear fencing, protective covers on all protruding moving parts, laser guarding that halts motion when the protected zone is broken, over-tonnage protection on turret punch presses, and grating-ruler offset-load detection on panel benders.
The right answer depends almost entirely on how repetitive your product range is. A coil line rewards repetition and punishes variety.
| Coil-to-part line | Sheet-fed punch and bend cell | Outsourced blanking | |
|---|---|---|---|
| Best for | Standardised ranges, continuous volume | Mixed ranges, medium batches | Low volume or unstable demand |
| Material cost per part | Lowest — coil price plus nesting | Sheet price, nesting within the sheet | Highest — includes supplier margin |
| Handling between stages | None — continuous | Stacked and moved between machines | Transport, inspection, storage |
| Work in progress | Minimal | Moderate | High — buffer stock required |
| Response to a design change | Program change, coil width permitting | Program change | Supplier lead time |
| Floor space | Largest footprint | Moderate | Smallest |
| Capital required | Highest | Moderate | Lowest |
| Suits thickness above 2 mm | No | Bending limited, punching capable | Supplier dependent |
| Does STON supply it? | Yes | Yes | Not applicable |
If your range changes frequently or your volume arrives in campaigns rather than continuously, we will recommend a sheet-fed cell instead. A coil line bought for a variable product mix spends its life waiting for coil changeovers, which is the most expensive way to be idle.
Figures below describe the direction and mechanism of the change. Actual results depend on your part mix, batch size and shift pattern — we model them against your own drawings before quoting.
| Item | Sheet, standalone machines | Coil-to-part line |
|---|---|---|
| Material input cost | Cut sheet, conversion premium per tonne | Coil, lowest cost per tonne |
| Material utilisation | Nesting limited by sheet size | Nesting across a continuous strip |
| Handling operations | Stack and move at every stage | None between stages |
| Work in progress | Buffers at each machine | Minimal, process interlocked |
| Blank flatness at the bender | Coil set and edge wave carried through | Levelled to ±1 mm/m² before cutting |
| Secondary positioning | Re-clamped at each machine | One reference through the line |
| Labour | Operators at each machine | Line supervision, not machine tending |
| Traceability | Per machine, manually linked | Unified control, data traceability across the line |
| Flexibility on new products | High | Coil width and thickness constrained |
Payback logic we use with customers: (annual labour released + reduction in rework and scrap + additional saleable output) ÷ installed equipment cost. We build this with your real numbers rather than publishing a headline figure that would not match your plant.
Welded and heat-aged uncoiler body, precision leveller with 40Cr rollers on self-aligning or needle bearings, fiber laser with process parameter database and AutoCAD-compatible programming, dual-temperature water cooling.
View the blanking line →
The complete chain from coil to formed part under one control system, with process interconnection, intelligent scheduling and data traceability. Layout planned around your product structure, capacity and building.
View the full line →
Punching, trimming, forming, louvring and rib pressing with automatic loading, sheet separation, positioning, unloading and stacking. ±0.1 mm accuracy, turret speed to 40 rpm.
View SF series →
Integrated feeding, positioning, bending and unloading with angle compensation and rapid program switching. Models to 2800 mm forming length, cast or welded frames, native automation interface.
View press arm type →
Links the stages so material is never set down. Compatible with most robotic arm and gantry brands, with vacuum pick-up that protects coated and filmed surfaces through the whole line.
View truss system →
For the parts that fall outside the coil width or run in short batches. Most coil-line customers keep a sheet laser alongside so the line is never stopped for a special.
View laser unit →Founded in 2006 and headquartered in Qingdao, one hour from major export ports and the airport. Casting, heat treatment, machining, welding, assembly and inspection all happen inside our own 20,000㎡ factory. That is why a configuration change for a full production line does not become a six-month subcontracting problem.
A line is a project, not a purchase. Layout, factory acceptance testing, shipping, installation, commissioning, training and handover are all part of the scope, and all of them are handled by STON's own engineers.
Specifications on this page verified against STON engineering documentation on 4 August 2026. Forming limits are confirmed against your own drawings before quotation. Published on 4 August 2026 · Last updated 4 August 2026 · Reviewed by Vicky Xu, Head of Overseas Sales.
A line is designed around your parts and your floor, not the other way round. Send the drawings and a building plan and we return a scoped layout, a utility list and an honest view on whether a coil line or a sheet-fed cell suits you better.
Prefer to talk first?
WhatsApp: +86 18153226091
Email: [email protected]
Send your requirements through our secure enquiry form. Our team will reply within 24 hours.
Whether you're upgrading an existing line or starting a new project, STON will customize a CNC solution for your production.
