Design rules for laser and bent parts
Our configurator checks these rules for every part. The figures on these pages come directly from our rule set: the same values the check in the shop calculates with. If you keep to the values, your part goes into production without queries.
Rules per material
Minimum flange, inside radius, distance from hole to bend edge and bend length depend on material and sheet thickness. The tables:
- Steel S235JR, DC01, galvanised steel. Laser cutting up to 20 mm, bending up to 6 mm.
- Stainless steel 1.4301, 1.4571. Laser cutting up to 20 mm, bending up to 6 mm.
- Aluminium AlMg3, AlMg1. Laser cutting up to 20 mm, bending up to 8 mm.
- Threads and countersinks M3 to M16: tap drill, suitable sheet thickness, distances.
Laser cutting
- Largest laser part (flat pattern)
- 2,980 × 1,490 mm
- Pure bent part without holes or cut-outs
- up to 3,000 × 1,500 mm
- Smallest part
- 8 mm edge length
- Smallest text height (lettering)
- 3 mm
Sheet thickness per material (laser cutting): Steel to 20 mm, Stainless steel to 20 mm, Aluminium to 20 mm, Copper to 8 mm, Brass to 8 mm. We check thicker sheets on request.
Smallest hole: at least 1 mm and at least 0.5 × sheet thickness; from 8 mm sheet at least 0.8 × sheet thickness, from 15 mm at least 1 × sheet thickness. This also applies to the narrow side of slots. Recommended is a hole as large as the sheet thickness: then the hole is round and clean.
Small parts: Parts under 15 mm (up to 5 mm sheet) or under 20 mm (thicker sheet) are held in the sheet with small micro-joints. A small mark remains at these points.
| Sheet thickness | Smallest hole | Hole recommended from | Smallest web | Web recommended from | Smallest edge distance | Edge recommended from |
|---|---|---|---|---|---|---|
| 0.5 mm | 1 mm | 1 mm | 0.5 mm | 2 mm | 0.5 mm | 1.5 mm |
| 0.8 mm | 1 mm | 1 mm | 0.5 mm | 2 mm | 0.5 mm | 1.5 mm |
| 1 mm | 1 mm | 1 mm | 0.5 mm | 2 mm | 0.5 mm | 1.5 mm |
| 1.5 mm | 1 mm | 1.5 mm | 0.75 mm | 2 mm | 0.75 mm | 1.5 mm |
| 2 mm | 1 mm | 2 mm | 1 mm | 2 mm | 1 mm | 2 mm |
| 2.5 mm | 1.25 mm | 2.5 mm | 1.25 mm | 2.5 mm | 1.25 mm | 2.5 mm |
| 3 mm | 1.5 mm | 3 mm | 1.5 mm | 3 mm | 1.5 mm | 3 mm |
| 4 mm | 2 mm | 4 mm | 2 mm | 4 mm | 2 mm | 4 mm |
| 5 mm | 2.5 mm | 5 mm | 2.5 mm | 5 mm | 2.5 mm | 5 mm |
| 6 mm | 3 mm | 6 mm | 3 mm | 6 mm | 3 mm | 6 mm |
| 8 mm | 6.4 mm | 8 mm | 4 mm | 8 mm | 4 mm | 8 mm |
| 10 mm | 8 mm | 10 mm | 5 mm | 10 mm | 5 mm | 10 mm |
| 12 mm | 9.6 mm | 12 mm | 6 mm | 12 mm | 6 mm | 12 mm |
| 15 mm | 15 mm | 15 mm | 7.5 mm | 15 mm | 7.5 mm | 15 mm |
| 20 mm | 20 mm | 20 mm | 10 mm | 20 mm | 10 mm | 20 mm |
Web is the material between two cut-outs, edge distance the material between cut-out and outer edge. From the smallest value we manufacture your part. Between the smallest and the recommended value, there may be temper colours or slight distortion; from the recommended value we manufacture without restriction.
We remove burrs on the cut edge on request: Deburring. Whether we punch or laser a part is decided per part: Punch-laser combination.
Bend
- Longest bend
- 3,000 mm part length (thin sheet)
- Smallest flange
- 8 mm, more depending on sheet thickness and die
- Inside radius
- 2 to 3.8 mm for 1 to 2.5 mm sheet, measured on our press brake
- Hem (pressed flat)
- up to 2 mm sheet
- Acute angle
- below 88° inside with special tooling
Thick sheet needs a lot of force to bend. That is why the possible bend length decreases with sheet thickness and depends on the material. The exact values are in the tables Steel, Stainless steel and Aluminium.
Corner reliefs: If two bends meet at a corner, the sheet needs a corner relief. At right-angled corners, for example on a box tray, the walls butt against each other: one wall runs to the outside corner, the other ends with a narrow gap in front of it. In the corner there is a round relief hole for thin sheet and a square relief of sheet-thickness width for thicker sheet. At other corners the bend lines end 0.5 × sheet thickness (at least 0.5 mm) before the corner. By this allowance the relief extends beyond the bend zone into the base sheet. At the end of a bend it is at least 1 × sheet thickness wide (at least 1 mm). Tabs on a tab along a bend line are at least 2 × sheet thickness and at least 3.2 mm wide.
Threads and countersinks
We tap threads into laser-cut tap holes from M3 to M16. Which size suits which sheet thickness and which distances apply is described under Threads and countersinks.
How we check your part
- The configurator checks every part against these rules when you upload or draw it and shows notes directly on the part.
- If a value is close to a limit, send a review request. We look at the part and get back to you.
- The check when you order is binding. The tables here show the state of our rule set at the last website update.
You will find tolerances and our inspection process under Quality and Tolerances. General design notes are below under Check values and notes in detail, background in the magazine: Bend radius and minimum flange; threads: Threads and countersinks in sheet metal.
Check values and notes in detail
Plan, check, configure to fit.
Most queries about an uploaded file arise at the same four points: holes too small, webs too narrow, flanges too short and holes too close to the bend edge. The following values come from our own production (laser cutting on a 3,000 × 1,500 mm sheet and bending on a CNC press brake) and explain the check values of our online configuration. Which features are recognised automatically depends on the input route and the file. Please note the check results shown and the limits of the check described below.
- Usable laser area: 2,980 × 1,490 mm; Minimum size 8 × 8 mm; parts under 15 × 15 mm with a small-part surcharge per piece
- Larger up to 3,000 × 1,500 mm: pure bent parts only (guillotine shear + press brake) without holes and cut-outs; beyond that not possible
- Smallest hole diameter: 0.5 × sheet thickness, never below 1 mm; recommended 1 × sheet thickness
- Narrowest web and smallest edge distance: 0.5 × sheet thickness, never below 0.5 mm; recommended 1 × sheet thickness (web at least 2 mm, edge at least 1.5 mm)
- Distance from hole to bend edge: value from the table, at least 2 × sheet thickness + inside radius
- Threads M3–M16 and countersinks: own rules (sheet thickness, edge distance) under Threads & countersinks
- Smallest flange: Minimum flange of the die, measured on our press brake, at least 8 mm The die is the lower bending tool: a rail with a groove. The sheet lies above it and a punch presses it into this groove from above. That creates the bend. The width of the groove is called the die opening W (column “Die” in the table, e.g. W 12 = 12 mm). The flange is the bent part of the sheet. It must rest on both edges of the groove, otherwise it slips in.Example: 3 mm steel runs over die W 24 → at least 17.9 mm.
- Inside radius: measured on our press brake per material, sheet thickness and die; between 2 mm and 3.8 mm for 1 to 2.5 mm sheet (table below)
- Bending up to 6 mm steel and stainless steel, 8 mm aluminium; bent parts up to 3,000 mm part length; smallest opening angle 30°; hems up to 2 mm
What we check automatically
In the Part designer and for STEP/DXF upload in the basket (check card), the same manufacturability check runs for every part. Each message has one of three levels:
| Blocking issue | The part cannot be made like this or not reliably. It gets no instant price and cannot be added to the basket if a check result is blocking. You change the design or send the part to our sales team with “Have it priced manually”. |
|---|---|
| Note | The part can be made, but one dimension is below our recommendation: the quality at this point is limited (burr, slight conicity, distortion). You confirm the note before ordering and we manufacture as designed. |
| On order review | A feature cannot yet be read by the automatic check. We check it by hand before the part goes into production and get in touch if anything needs to change. |
In detail, we check:
- Size: Flat pattern larger than 2,980 × 1,490 mm (in any rotation): blocked in the part designer and for STEP/DXF upload; a pure bent part up to 3,000 × 1,500 mm can be ordered in the bent part configurator (see Part size: three zones). Part smaller than 8 × 8 mm: blocked, otherwise the part falls through the grate; one side under 8 mm: note.
- Sheet thickness: Thickness not in the range of the selected material: blocked, with the next available thicknesses named.
- Holes, slots, webs, edge distance: below the minimum value: blocked; between minimum and recommended value: note (values in the table below).
- Cut-outs at the bend edge: closer than the table value “Hole → bend edge” or in the bend zone: note, the hole may deform during bending.
- Bendability: Sheet thickness above the bending limit of the material, no suitable die, opening angle below 30°, hem over 2 mm, flange shorter than the minimum flange, bend length above the press or thickness limit: each blocked.
- Bend radius: designed inside radius smaller than the tool radius or clearly different from the expected actual radius: note with the actual radius the tool produces.
- Deburring: shorter side of the flat pattern over 250 mm: note; we then do any requested deburring by hand (Deburring).
- Not yet read from STEP: Hole dimensions and flange lengths are checked during order review. In the part designer, both are checked in full.
Laser parts: format and sheet thickness
| Usable laser area | 2,980 × 1,490 mm (sheet 3,000 × 1,500 mm less the cutting margin); the flat pattern must fit in any rotation |
|---|---|
| Minimum size | 8 × 8 mm. Smaller parts fall through the grate or tilt; we are happy to check by hand whether they can be made with micro-joints or cut from a larger part |
| Small-part surcharge | Laser parts whose flat pattern is below 15 mm in one direction are held in the sheet with micro-joints and deburred individually. Per piece, by part weight: under 5 g €1.50, 5–20 g €1.00, 20–50 g €0.50, from 50 g no surcharge (net). The surcharge is shown as a separate line with the price. We are currently pricing parts under 15 mm manually – the enquiry will be reviewed. |
| Steel (S235JR) | 1 to 10 mm; bending up to 6 mm |
| Stainless steel (1.4301) | 0.5 to 6 mm; bending up to 6 mm |
| Aluminium (AlMg3) | 0.5 to 10 mm; bending up to 8 mm |
| Limit of the lasers | steel 20 mm, stainless steel 20 mm, aluminium 20 mm, copper 8 mm, brass 8 mm (largest sheet thickness of our machines). Available are the thicknesses in the material selection; for thicker parts please send a review request |
| Deburring | by machine up to 250 mm part width, above that by hand (Deburring) |
The material selection in the configurator shows the individual thicknesses available per material; for a thickness we do not stock, the check names the next available thicknesses.
Part size: three zones
The flat pattern is decisive, in any rotation: the long side against the length, the short side against the width. Our largest sheet measures 3,000 × 1,500 mm, the press brake is 3,000 mm long. The laser needs a cutting margin.
| Up to 2,980 × 1,490 mm | Everything possible: holes, cut-outs, free contour, tray, circular blank, hole pattern and bends. |
|---|---|
| Over 2,980 × 1,490 up to 3,000 × 1,500 mm | Pure bent parts only: rectangular blank on the guillotine shear, bends on the press brake. No holes, no cut-outs, no free contour and no laser templates (e.g. tray with corner notch). Order such parts in the Bent part configurator or as a Cut-to-size. |
| Over 3,000 × 1,500 mm | Cannot be made. Please split the part or ask for it as a profile or special request. |
Holes, slots and webs
In laser cutting, the sheet thickness determines how small a cut-out may be: the beam needs room to blow the melt downwards. A hole whose diameter is smaller than the sheet thickness becomes slightly conical and may have burrs; below half the sheet thickness it is no longer process-reliable. A web narrower than 0.5 × sheet thickness burns away during cutting. “Minimum” is the blocking limit, “recommended” the limit for a note.
| Hole diameter | at least 0.5 × sheet thickness, never below 1 mm; from 8 mm sheet at least 0.8 ×, from 15 mm 1 × sheet thickness; recommended 1 × sheet thickness (for 3 mm sheet: at least Ø 1.5 mm, recommended Ø 3 mm) |
|---|---|
| Slot width and smallest dimension of a cut-out | like hole diameter: at least 0.5 × sheet thickness, never below 1 mm; recommended 1 × sheet thickness |
| Web between two cut-outs | at least 0.5 × sheet thickness, never below 0.5 mm; recommended 1 × sheet thickness, never below 2 mm (for 3 mm sheet: at least 1.5 mm, recommended 3 mm) |
| Distance from cut-out to outer edge | at least 0.5 × sheet thickness, never below 0.5 mm; recommended 1 × sheet thickness, never below 1.5 mm (for 3 mm sheet: at least 1.5 mm, recommended 3 mm) |
| Inside corners | The laser beam has a kerf of a few tenths of a millimetre; a sharply designed inside corner therefore gets a small radius. If you need a defined corner, design a radius or a corner relief |
We also manufacture more finely designed parts on request: holes that are too small can be marked by centre punching or drilled. Such parts need an individual check and are not part of the instant price. The “Have it priced manually” button submits them.
Holes at the bend edge
When bending, the material flows in the area of the bend. If a hole lies in this deformation zone, it is drawn oval and the edge distorts. Therefore keep at least 2 × sheet thickness + inside radius between hole edge and bend line, for wider dies the value of the die measured on our press brake (column “Hole → bend edge” in the table per material). If a cut-out is closer or touches the bend zone, the check shows a note; you confirm the deformation at this point before ordering. If the hole has to be closer, the usual solution is a relief cut: the hole is extended into the bend zone as a slot, so that no web remains on the bend line that could distort.
Bending: flanges, radius and angle
Bending takes place between two tools. At the bottom lies the Die: a steel rail with a V-shaped groove. From above, the punch comes down and presses the sheet into this groove. The width of the groove is called the Die opening and appears in the table as the “W” value: W 12 means 12 mm. The thicker the sheet, the wider the groove. We mainly bend on CDW dies (Consistent Die Width) with a 28° die; which die a sheet gets depends on material and sheet thickness (column “Die” in the table per material).
This results in two limits. The Flange (i.e. the bent part of the sheet) must rest on both edges of the groove. If it is shorter, it slips into the groove and the bend becomes crooked. That is why the minimum flange of the die measured on our press brake applies, at least 8 mm; a shorter flange is blocked. And the Inside radius (the curve on the inside of the bend) results from die, material and sheet thickness during air bending. We have measured it on our press brake for each die. With thin sheet it is usually larger than the sheet thickness(between 2 mm and 3.8 mm for 1 to 2.5 mm sheet). Design with the inside radius from the table per material, then outside dimensions and flat pattern are correct. The check shows you the expected actual radius.
Two limits decide how thick and how long we bend. The first is force: thick and strong sheets need more force, so the possible bend length becomes shorter with sheet thickness (table below). The second limit is the material: we bend steel S235JR and stainless steel 1.4301 up to 6 mm, aluminium AlMg3 up to 8 mm. We cut thicker sheets but do not bend them. The check reports this as blocked and offers the part as a laser part without bends.
| Longest bend | 3,000 mm part length; less depending on material and sheet thickness (see table “Bend length per sheet thickness”) |
|---|---|
| Acute angles | We bend inside angles below 88° with a slim 28° upper tool; it carries less load, so the possible bend length is shorter |
| Smallest opening angle | 30° between the flanges (bend angle 150°); sharper bends are blocked |
| Hem (180°) | up to 2 mm sheet thickness, blocked for thicker sheet |
| Angle tolerance | ± 0.5° (ACB angle measurement, typically ± 0.3°); please request tighter tolerances in the remarks. All tolerances: Tolerances |
Bend length per sheet thickness
Longest orderable bend length with the standard upper tool in mm (guide values; “–” = cannot be bent like this). Please send a review request for longer parts.
| Material | 1 mm | 2 mm | 3 mm | 4 mm | 5 mm | 6 mm | 8 mm |
|---|---|---|---|---|---|---|---|
| Steel | 3,000 | 3,000 | 3,000 | 1,640 | 3,000 | 2,190 | – |
| Stainless steel | 3,000 | 3,000 | 2,260 | 1,410 | 2,310 | 1,510 | – |
| Aluminium | 3,000 | 3,000 | 3,000 | 3,000 | 2,320 | 1,490 | 2,170 |
Die, minimum flange and inside radius per material
Per material and sheet thickness: which die we use, the minimum flange (outside dimension, measured on our press brake, never below 8 mm), the inside radius at 90° with the standard tool (also measured), the minimum distance from hole edge to bend edge and the longest orderable bend length. Guide values; the check in the configurator uses the same values.
| Sheet thickness | Die | Flange min. | Inside radius | Hole → bend edge | Bend length max. |
|---|---|---|---|---|---|
| 0.5 mm | CDW-B W8/28° | 8 mm | 1 mm | 5 mm | 3,000 mm |
| 1 mm | CDW-B W16/28° | 11.7 mm | 2.8 mm | 9.7 mm | 3,000 mm |
| 1.5 mm | CDW-B W16/28° | 11.9 mm | 3.3 mm | 9.7 mm | 3,000 mm |
| 2 mm | CDW-B W12/28° | 9.4 mm | 2 mm | 7.4 mm | 3,000 mm |
| 2.5 mm | CDW-B W16/28° | 12.3 mm | 2.5 mm | 9.7 mm | 2,880 mm |
| 3 mm | CDW W24/28° | 17.9 mm | 4.9 mm | 14.6 mm | 3,000 mm |
| 4 mm | CDW W24/28° | 17.9 mm | 4 mm | 14.6 mm | 1,640 mm |
| 5 mm | EV W50/30° | 39.1 mm | 8 mm | 35.9 mm | 3,000 mm |
| 6 mm | EV W50/30° | 39.1 mm | 9 mm | 35.9 mm | 2,190 mm |
| 8 mm | can be ordered as a blank | ||||
| Sheet thickness | Die | Flange min. | Inside radius | Hole → bend edge | Bend length max. |
|---|---|---|---|---|---|
| 0.5 mm | CDW-B W8/28° | 8 mm | 1 mm | 5 mm | 3,000 mm |
| 1 mm | CDW-B W16/28° | 11.7 mm | 3.5 mm | 9.7 mm | 3,000 mm |
| 1.5 mm | CDW-B W16/28° | 11.9 mm | 3.7 mm | 9.7 mm | 3,000 mm |
| 2 mm | CDW-B W16/28° | 12.1 mm | 3.8 mm | 9.7 mm | 3,000 mm |
| 2.5 mm | CDW-B W16/28° | 12.3 mm | 3.8 mm | 9.7 mm | 1,990 mm |
| 3 mm | CDW W24/28° | 17.9 mm | 5.7 mm | 14.6 mm | 2,260 mm |
| 4 mm | CDW W28/28° | 20.7 mm | 6.7 mm | 18.1 mm | 1,410 mm |
| 5 mm | EV W50/30° | 39.1 mm | 10.4 mm | 35.9 mm | 2,310 mm |
| 6 mm | EV W50/30° | 39.1 mm | 9 mm | 35.9 mm | 1,510 mm |
| 8 mm | can be ordered as a blank | ||||
| Sheet thickness | Die | Flange min. | Inside radius | Hole → bend edge | Bend length max. |
|---|---|---|---|---|---|
| 0.5 mm | CDW-B W8/28° | 8 mm | 1 mm | 5 mm | 3,000 mm |
| 1 mm | CDW-B W16/28° | 11.7 mm | 3.4 mm | 9.7 mm | 3,000 mm |
| 1.5 mm | CDW-B W16/28° | 11.9 mm | 3.4 mm | 9.7 mm | 3,000 mm |
| 2 mm | CDW-B W16/28° | 12.1 mm | 3.8 mm | 9.7 mm | 3,000 mm |
| 2.5 mm | CDW-B W16/28° | 12.3 mm | 3.8 mm | 9.7 mm | 3,000 mm |
| 3 mm | CDW-B W16/28° | 12.5 mm | 3.7 mm | 9.7 mm | 3,000 mm |
| 4 mm | CDW W28/28° | 20.7 mm | 4 mm | 18.1 mm | 3,000 mm |
| 5 mm | CDW W28/28° | 20.7 mm | 6.5 mm | 18.1 mm | 2,320 mm |
| 6 mm | CDW W28/28° | 20.7 mm | 9 mm | 21 mm | 1,490 mm |
| 8 mm | EV W50/30° | 39.1 mm | 12 mm | 35.9 mm | 2,170 mm |
File upload
For the instant price we need a STEP file (.step or .stp, AP214 or AP203) of the finished, bent part, not of the flat pattern; we calculate the flat pattern ourselves. One body per file, modelled in millimetres, without assemblies. The calculation cannot read countersinks, chamfers and threads: the check removes them and shows a note; please give them as a remark on the item. Upload pure blanks as DXF , at a scale of 1:1 in millimetres with closed contours. If you have no CAD file, configure the part directly in the browser: Bent part and cut-to-size or Part designer for trays, cut-outs and holes.
After uploading, you see the check card with blocks and notes. If something is blocked or a file cannot be priced automatically, such as a part under 8 × 8 mm, send the part to our sales team with “Have it priced manually”; you receive a quotation by email within one working day. You confirm notes before ordering. Before production, we also look through every part and get in touch before we make a part that will not turn out cleanly.
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