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Panel benders form stainless to 1.2 mm at full bend length. That covers most cabinet and panel work, and none of the heavy worktop work. Here is exactly where the line falls.
A STON cast-iron frame panel bender forms stainless steel up to 1.2 mm at full bending length; a welded frame reaches 1.0 mm. That is the honest number, and it is lower than for cold-rolled steel because stainless work-hardens and springs back harder. It matters because stainless product specifications routinely sit at 1.5 mm and above — commercial worktops in particular.
Inside the window, a panel bender is excellent: cabinet doors, side panels, splash backs, shelf panels, hood panels and equipment housings in 0.8 to 1.2 mm are exactly the four-sided folded geometry it is built for, with the added benefit that vacuum pick-up never drags a brushed or mirror finish across a back gauge. Outside the window — 1.5 mm and thicker worktops, heavy frames, and deep-drawn sink bowls — the parts belong on a press brake or on press tooling, and no configuration option changes that. We identify which of your parts fall on each side of the line 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 →
Most stainless cabinet and equipment panels are between 0.8 and 1.2 mm. The parts that fall outside are usually worktops and structural members — which is why nearly every stainless shop runs a press brake alongside.
Stainless work-hardens during forming and demands substantially more force than cold-rolled at the same gauge, which is why the panel bender limit is 1.2 mm rather than 2.0 mm. Specifications drift upwards easily — a 1.5 mm worktop looks like a small change from a 1.2 mm door, but it is on the other side of the machine boundary.
The same bend program that produces a correct angle in mild steel will under-bend stainless, and the error grows with thickness. Closed-loop servo control with rapid compensation adjustment along the bend line is what makes stainless angle repeatable across a batch, rather than something an operator re-establishes on each run.
Brushed, mirror and patterned stainless is specified by the customer and matched across a whole installation. A scratched panel is remade, not polished, at full material cost. Vacuum pick-up moves the blank in the air, protective film stays on through forming, and grain direction is controlled at the nesting stage.
For stainless work the first question is not volume — it is what proportion of your parts sit above 1.2 mm. That ratio decides the whole machine list.
This page exists because of one row. Read the stainless line, check it against your worktop specification, and bring the answer to the first call.
| Parameter | Panel bender — cast frame | Panel bender — welded frame | Notes |
|---|---|---|---|
| Stainless steel | ≤1.2 mm | ≤1.0 mm | 1.5 mm and above needs a press brake |
| Cold-rolled steel | ≤2.0 mm | ≤1.5 mm | For carbon steel sub-frames |
| Aluminium | ≤2.5 mm | ≤2.5 mm | Alloy dependent |
| Max forming size | 1000 × 1000 up to 2800 × 1500 mm | By model | |
| Bending height | 5 mm minimum / 170, 300 or 400 mm maximum | By configuration | |
| Min four-sided inner size | approx. 140 × 190 mm | Small hygienic trims may fall below | |
| Angle accuracy | approx. ±0.5°/m | Springback compensation applied | |
| Straightness | approx. 0.2 mm/m | Decides flush joints on cladding | |
| Deep-drawn sink bowls | Not possible — press tooling process, not supplied | Different supplier | |
| Utilities | Three-phase 380 V, 0.6 MPa air | Configured to destination voltage | |
Stainless cabinet doors, side panels, splash backs, shelf panels, hoods and equipment housings at 0.8–1.2 mm, folded on all four sides, with a finish that must not be touched.
Commercial worktops at 1.5 mm and above at full bend length, deep-drawn sink bowls, heavy structural frames, and roll-formed profiles. Three different processes, none of them a panel bender.
Worktops, heavy frame members, thick brackets and any stainless part above 1.2 mm. In stainless fabrication the press brake is not a backup machine — for many shops it carries half the product.
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. For the finished product, EN 10088-2 covers stainless sheet delivery conditions and surface finishes, and EN 1672-2 sets hygiene requirements for food processing machinery including cleanable surfaces and edge design. Both apply to your product rather than to the machine, but the folded edge geometry they require is produced at the forming stage.
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.
Stainless fabrication is the clearest case in sheet metal for needing more than one process. The split is decided by thickness and by whether the part is folded or drawn.
| CNC panel bender | CNC press brake | Press tooling | |
|---|---|---|---|
| Stainless thickness | ≤1.2 mm at full length | Set by tonnage and tooling | Set by the press and die |
| Typical stainless parts | Doors, side panels, splash backs, housings | Worktops, frames, heavy brackets | Sink bowls, drawn shells |
| Four-sided panels | Single clamping | 4 rotations | Not applicable |
| Finish protection | Vacuum pick-up, film retained | Manual handling each bend | Die contact |
| Springback control | Closed loop plus rapid compensation | Crowning plus operator | Built into the die |
| Tooling lead time | Custom knives, quoted with machine | Standard tooling | Long — dedicated die |
| Does STON supply it? | Yes | Yes | No — different process |
If most of your output is 1.5 mm worktops and drawn sink bowls, a panel bender is the wrong first purchase and we will say so. The right conversation in that case is about press brake capacity, not bending automation.
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 | Press brakes only | Panel bender cell |
|---|---|---|
| Contact with the finish | Dragged across the back gauge each bend | None — vacuum pick-up |
| Scrap from surface damage | The largest scrap category in stainless | Largely eliminated |
| Springback consistency | Re-established by the operator each run | Stored compensation values |
| Operators per large panel | 2 | 1, or unattended with loading |
| Angle consistency across a batch | Drifts with operator and shift | approx. ±0.5°/m |
| Changeover between cabinet sizes | Tool swap and gauge reset | Program recall |
| Parts above 1.2 mm stainless | Handled | Stay on the press brake |
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.
Vacuum-gripped feeding for filmed and finished stainless, cast-iron frame rated to 1.2 mm stainless at full bend length. Patented 360° rotating suction feeding, grating-ruler offset-load detection, cabinet air conditioning.
View suction cup type →
For 1.5 mm and heavier stainless worktops, frames and brackets outside the panel bender window. 63 t to 320 t, DELEM or ESA control, mechanical compensation, high-precision grating ruler.
View PBS series →
Fiber laser blanking with smooth, burr-free cuts — essential where the cut edge stays visible on a stainless panel. Exchange table loads the next sheet while the current one is cut.
View laser unit →
Dead edge, offset and arc bending for hygienic rolled and hemmed edges. Minimum folded height 4 mm, 42CrMo forged blank holder, suction feeding that keeps protective film intact.
View folding machine →
Fixing patterns, ventilation and service cut-outs in one clamping. Brush and steel-ball composite table carries filmed stainless without scoring; stainless-steel table edging resists scratching.
View SF series →
On stainless, automation is justified by scrap as much as by labour. Native interface on every panel bender, vacuum pick-up that never touches the finished face, compatible with most robot brands.
View truss system →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 stainless panel cell does not become a six-month subcontracting problem.
Stainless material cost per part is high, so a machine problem becomes a scrap problem quickly. Fast diagnosis matters more here than in almost any other sheet metal sector.
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.
One drawing decides most of this conversation. Send your thickest stainless part alongside your largest panel and we will tell you within 24 hours what sits inside the 1.2 mm window and what does not.
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