Key takeaways
- Use 1.5 mm CRCA for the body, 1.2 mm for removable covers and 2.0–3.0 mm for base plates; 1.0 mm panels below 400 mm wide bow during cutting unless the power is turned down.
- The laser holds hole positions inside ±0.1 mm and a 0.15–0.3 mm kerf on 1.5 mm CRCA, but bending opens hole-to-hole tolerance across a bend to ±0.5 mm.
- A 600 × 400 mm cover with 24 holes and a 300 × 200 mm cutout carries 3.84 m of cut and 30 pierces, about 25 seconds of beam time on the 12 kW laser.
- Twelve covers fit on a 1,250 × 2,500 mm sheet at 92% utilisation; dropping to eleven raises material cost per part by roughly 9%.
An enclosure is a tolerance stack with a lid on it. The laser sets the hole positions, the brake sets where the flanges land and 70 µm of powder decides whether the lid still shuts. Laser cutting sheet metal enclosures is a thickness and tolerance decision before it is a price decision, and three numbers settle it: material thickness, cut tolerance and cost per panel.
On 1.5 mm CRCA the kerf runs 0.15–0.3 mm and hole positions hold inside ±0.1 mm off the machine. Bend the same panel and the tolerance opens to ±0.2 mm on a flange and ±0.5 mm between holes that sit on opposite sides of a bend. That gap between the laser and the brake is where most enclosure complaints start, and buying a more accurate cutting machine does not close it.
What follows is the thickness set for a typical electrical or equipment enclosure, the tolerance each operation contributes, a cost example you can reproduce from your own cut length, and the fields that belong on the drawing so a repeat release behaves like the first one.
What thickness should a sheet metal enclosure panel be?
Take 1.5 mm CRCA for the body, 1.2 mm for removable covers and doors, and 2.0–3.0 mm for base plates and any panel carrying a transformer or a busbar. The body thickness is set by stiffness rather than strength: panel stiffness rises with the cube of thickness, so going from 1.2 mm to 2.4 mm makes a panel eight times harder to deflect, which is why 3.0 mm base plates feel disproportionate next to a 1.5 mm side.
Gasket compression is the second constraint. A door with a neoprene gasket needs a flange that stays flat within about 1 mm across its length, and that is a forming and welding result, not a thickness result. A 2.0 mm door that is twisted will leak where a straight 1.2 mm door seals.
Welding sets the lower bound. Below 1.2 mm, MIG welding a corner pulls the panel out of flat unless the joint is flanged or the panel is clamped to a fixture, and the distortion then shows up as a lid that rocks on three corners. We weld 1.2 mm enclosures with a low-current programme and a fixture rather than with a lighter gauge and hope.
The material range for custom parts at Ganesh is 0.8–40 mm, and the 12 kW laser cuts to 20 mm. An enclosure that needs 25 mm plate is a machined or waterjet part, not a laser-cut one.
Which tolerance belongs to the laser and which to the brake?
The laser owns position on the flat; the brake owns everything that happens after it. Cut features on 1.5 mm CRCA hold ±0.1 mm on position and ±0.15 mm on diameter, and the cut edge classifies under ISO 9013, which covers laser cuts from 0.5 mm to 32 mm and grades the edge on perpendicularity and mean height.
A class 2 cut on 1.5 mm mild steel lands around Rz 20–50 µm. That is smooth enough for a powder coat to cover without a visible witness line, and rough enough that a gasket sitting on the cut edge will not seal against it. Seal on a face, never on a cut edge.
Bending adds the larger error. A 90° bend on 1.5 mm CRCA springs back 1–1.5°, and the control compensates for most of it, but the residual angle error is still about ±0.5°. Over a 100 mm flange that moves the tip by 100 × sin 0.5°, or 0.9 mm, and every hole on the flange moves with it. Flange length itself holds ±0.2 mm because the bend line is set by the back gauge, not by the springback.
How to measure the tolerance you put on the drawing
Measure position on the flat and measure it again after forming, because they are two different acceptance decisions. On the flat, a pin gauge or a vision system checks the pattern against the datum in a few seconds per panel. After forming, the same pattern needs a checking fixture that locates on the bend, or a CMM program that reports the flange angle and the hole position together.
Where the drawing is silent, ISO 2768-1 supplies general tolerances for parts formed from sheet metal, and its medium class allows ±0.2 mm on a 30–120 mm dimension. That is looser than the laser can hold and looser than a mating cover usually needs, which is why an enclosure drawing should carry an explicit tolerance on the hole pattern rather than inherit the general class by default.
| Parameter | Typical enclosure callout | Ganesh limit or note |
|---|---|---|
| Body material | 1.5 mm CRCA | 1.2–2.0 mm for bodies up to 800 mm; 0.8 mm is the floor for custom parts |
| Cover and door material | 1.2 mm CRCA | 1.0 mm possible, but flatness and gasket compression suffer |
| Base plate | 2.0–3.0 mm | Laser cuts to 20 mm; above that the part moves to another process |
| Cut kerf | 0.15–0.3 mm | 0.2 mm nominal on 1.5 mm CRCA; the nest allowance must use the real kerf |
| Hole position on the flat | ±0.1 mm | ±0.1 mm; ±0.15 mm on holes under 3 mm diameter |
| Hole diameter | ±0.15 mm | ±0.15 mm; below 1.0 mm the pierce dominates and the hole tapers |
| Cut edge quality | ISO 9013 class 2 | Class 2 on 1.5 mm; class 1 available at lower speed and higher cost |
| Flange length after bending | ±0.2 mm | ±0.2 mm on a 100 mm flange; ±0.3 mm beyond 500 mm |
| Hole-to-hole across a bend | ±0.5 mm | ±0.5 mm typical; tighter only with a checking fixture and an agreed sampling plan |
| Bend angle | ±0.5° | ±0.5° on the 200 T brake; ±0.3° on a repeat programme |
| Panel flatness | 1 mm | 1 mm over 600 mm; thin panels need a supported nest and a stress-relieved cut |
| Powder coat DFT | 60–80 µm | 70 µm nominal over seven-tank pretreatment |
The cost of one 600 × 400 mm cover, worked
Cost per panel follows cut length and pierce count, not sheet area. Take a 600 × 400 mm cover in 1.5 mm CRCA with a 300 × 200 mm cutout, 24 holes of 8 mm and four 20 × 10 mm slots.
The outline is 2 × (600 + 400) = 2,000 mm. The cutout adds 2 × (300 + 200) = 1,000 mm. The 24 holes add 24 × π × 8 = 603 mm, and the four slots add 4 × 60 = 240 mm. Total cut length is 3,843 mm, or 3.84 m, and the pierce count is 30: one for the outline, 24 for the holes, four for the slots and one for the cutout.
At an average 15 m/min including acceleration and corner slowdowns, 3.84 m takes 0.256 min, or 15.4 s. Thirty pierces at 0.3 s each add 9 s. Beam-on time is roughly 25 s per cover, and that is the number the cutting rate multiplies, not the 600 × 400 mm footprint.
Nesting decides the material line. A 1,250 × 2,500 mm sheet is 3.125 m². With a 10 mm web, each cover occupies a 610 × 410 mm pitch, so two fit across the 1,250 mm width and six fit along the 2,500 mm length: twelve covers per sheet. Twelve covers at 0.24 m² each is 2.88 m², which is 92% utilisation of the sheet. Drop to eleven and utilisation falls to 84.5%, so the material cost per part rises by about 9% for losing one part from the nest.
The sheet itself weighs 36.8 kg: 3.125 m² × 1.5 mm × 7,850 kg/m³. At twelve parts, each cover carries 3.07 kg of material, and at 92% utilisation the scrap allowance takes it to 3.33 kg. Multiply that by the material rate, add beam time at the machine rate, then add bending, welding and coating. Cutting the same part in a different thickness changes both lines, and the laser cutting capability page lists the range the machines cover.
Thickness is not a linear multiplier, and the 2.0 mm version of the same cover shows why. The sheet weighs 49.1 kg, so material per part rises from 3.07 kg to 4.09 kg, a 33% increase. The cut slows from about 15 m/min to 11 m/min, so the 3.84 m contour takes 21 s instead of 15.4 s and the total with pierces moves from 25 s to 30 s, a 20% increase on machine time. Going from 1.5 mm to 2.0 mm therefore adds a third to the material line for a panel that is 2.37 times as stiff in bending. On a cover that carries nothing, that is a poor trade.
On a door that has to hold a 1 mm gasket gap over 900 mm, the same extra thickness is usually the cheapest fix available.
Thin panels, dross and the coating that follows
Dross is the tell for a cut that will fail inspection. On 1.5 mm CRCA cut with oxygen, a little adherent dross on the underside is normal and comes off with a knife or a deburr pass. On stainless and aluminium cut with nitrogen, a clean underside is expected, and re-cast dross on the edge means the assist pressure or the focus is wrong.
The coating consequence is direct. Powder covers a rough edge, but it does not fill a dross lump: a 0.3 mm nodule on a flange face becomes a high spot that lifts the lid and shows as a shadow line after curing. We deburr cut edges on enclosure panels before pretreatment, and the deburring and edge quality guide covers how much edge preparation each finish actually needs.
Two more details decide whether the panel survives the line. First, cut the earth stud hole and any masking zone as a plain round hole, because a masked square with powder bridging the corner is a rework ticket. Second, put the grain direction on the drawing if the panel is visible; CRCA rolls have a direction, and a large flat door formed across the grain shows a different surface than one formed along it.
What Ganesh runs for enclosure panels
Enclosure panels run on the 12 kW fibre laser with the 40 ft × 16 ft bed, which cuts a 2,400 mm panel and its full hole pattern in one pass without a splice. Two 6 kW and two 3 kW machines take the smaller covers and the repeat work, so a mixed release does not queue behind one long panel. Cutting covers mild steel, CRCA, stainless, aluminium, brass and copper, which matters when an enclosure needs a stainless back plate and an aluminium door in the same kit.
Forming follows on the 200 T, 5-axis brake with the 4,450 mm bed and a Delem control, to 10 mm thickness, with a stored programme per part number so a repeat release bends to the same angle. Panels then go through the seven-tank pretreatment, the 18 ft × 14 ft powder booth and the curing oven on the same site, which is what keeps the coating allowance consistent between the first article and the fiftieth.
The laser cutting capability page lists the machines and the materials, and the laser cutting and fabrication hub collects the thickness, tolerance and nesting articles behind this one. Where a panel is cut and bent as one part, the laser-cut and bent enclosure guide covers the bend sequence; where the question is which thickness survives a given load, the laser cutting tolerances for OEM parts article goes deeper on measurement.
What to put on the enclosure drawing
- Material and thickness, with the grade, not just "MS". CRCA D or DD changes the bend allowance and the springback.
- Flat pattern or formed dimensions, stated explicitly. If the drawing gives formed dimensions, the bend deduction is ours to apply and yours to confirm.
- Hole and cutout positions with a tolerance, and a datum. A pattern toleranced from three different edges will be inspected three ways.
- Bend lines, radius and angle, with the inside radius called out. R2 is the default on 1.5 mm CRCA; R1 needs a sharp tool and shows a witness mark.
- Gasket face flatness where the enclosure is sealed, with the measurement method.
- Coating system, colour and DFT, plus a masking schedule for earth points, studs and threads.
- Marking and traceability, if the panel carries a serial or a customer part number that has to survive pretreatment.
When laser cutting is the wrong route for an enclosure
Laser cutting loses to stamping once the annual volume is high enough to amortise a tool, which for a simple cover is a question of tens of thousands of parts rather than hundreds. It also loses on thickness: above 20 mm the cut slows and the edge quality drops, and a 25 mm flange is a plate job.
It is the wrong route when the enclosure needs a rolled edge, a drawn corner or a fine-blanked edge with a controlled shear zone. Those are forming operations, and a laser-cut flat cannot imitate them. It is also the wrong route when the only tolerance that matters is the flatness of a large thin door: cutting cannot fix a panel that bows, and the answer is a thicker gauge, a stiffening rib or a different material.
For everything between a prototype cover and a 5,000-off production panel, the decision is usually settled by the nest. Send the DXF with the material, thickness and finish through the quotation route and the engineering team will return the cut length, the nest count and the bend programme before the price.
Frequently asked questions
What thickness should an electrical enclosure panel be?
1.5 mm CRCA is the working default for a body panel up to about 800 mm tall, 1.2 mm for removable covers and doors, and 2.0–3.0 mm for base plates and panels that carry a transformer. Below 1.2 mm, gasket compression and weld distortion become harder to control than the material saving is worth.
What tolerance can laser cutting hold on an enclosure?
±0.1 mm on hole and cutout position on 1.5 mm CRCA, and ±0.15 mm on hole diameter, measured on the flat. After bending, hole-to-hole across a bend opens to ±0.5 mm, which is the figure to put on the drawing for the finished part.
Why does a laser-cut enclosure panel bow after cutting?
Heat input on thin sheet. A 1.0 mm panel cut at full power over a 600 mm length absorbs enough heat to bow 1–2 mm, and a bowing panel lifts off the nest and changes the kerf. Lower power, higher speed, nitrogen assist and a well-supported nest reduce it.
How is laser cutting cost calculated for an enclosure panel?
From cut length, pierce count, material mass and nesting utilisation. A 600 × 400 mm cover carries about 3.84 m of cut and 30 pierces; the machine time follows from those two numbers, and the material cost from the sheet area divided by the number of parts nested.
Can laser cutting produce an IP65 enclosure?
The cut panel can be accurate enough, but the seal is made by the gasket, the flange flatness and the weld, not by the cut edge. Specify 1.0 mm flatness on the gasket face, a continuous weld on the joint and a masked earth point, then test the assembly rather than the panel.
Sources and further reading
- ISO 9013:2017 — Thermal cutting: classification of thermal cuts, covering laser cuts from 0.5 mm to 32 mm · reviewed 3 Nov 2026
- ISO 2768-1:1989 — General tolerances for linear and angular dimensions, including parts formed from sheet metal · reviewed 3 Nov 2026
- BIS — IS 513 cold reduced carbon steel sheet and strip, the grade behind CRCA enclosures · reviewed 3 Nov 2026
Send the enclosure DXF and the revision
Include the material, thickness, finish and quantity. We check the cut path, the bend allowance and the nest before quoting, and flag the features that will not hold tolerance.
Send a DXF
