What each technology does to duct sheet
Plasma melts a kerf with an ionised air jet at 45–125 A. On 0.5–1.5 mm galvanised it cuts fast, leaves a heat-affected zone and some dross on the underside, and a kerf of roughly 1.5–2 mm that CAM software compensates for. The torch consumables (nozzle, electrode, shield) wear with every start and are the running cost. Fume from zinc is real and needs extraction. Fiber laser melts a far narrower kerf (about 0.1–0.3 mm) with a focused beam and blows it clear with assist gas; on duct gauges the edge is clean and dross-free, holes and slots come out sharp, and there is nothing to replace but the protective lens and nozzle occasionally. Stainless and aluminium, which plasma cuts with a rough edge and heavy dross, cut cleanly on a laser. The price is capital cost and the need for clean assist gas and a stable power supply.
The comparison, for duct work
| Factor | CNC plasma table | Fiber laser table |
|---|
| Typical duct-shop machine | 5×10 ft or 1550×4000/5000 mm bed; 45–65 A air plasma | 1500×3000 or 1500×4000 mm bed; 1.5–3 kW fiber source |
| Material range on one machine | Galvanised, mild steel, aluminium, stainless to several mm; 0.4–4 mm on the Taokron SBPC | Galvanised, stainless, aluminium; 0.5–6 mm (2 kW) or 0.8–8 mm (3 kW) on the Taokron SBLC |
| Edge on 0.7 mm galvanised | Slight dross underside, heat tint; fine for seamed fittings | Clean, dross-free, no rework |
| Edge on stainless and aluminium | Rough with dross; needs deburring | Clean; the main reason duct shops buy a laser |
| Kerf and accuracy | About 1.5–2 mm kerf; ±0.5 mm typical | About 0.1–0.3 mm kerf; ±0.1 mm typical; sharp small holes |
| Cutting speed at 0.5–1.5 mm | Fast: 7–8 m/min on the SBPC; nesting and loading dominate cycle time | Comparable or faster on thin sheet; rapid traverse and piercing are quicker |
| Running cost | Torch consumables per set plus compressed air and power; the more pierces, the more sets | Assist gas (air or nitrogen), power, occasional lens and nozzle; near-zero consumables on air |
| Fume and noise | Zinc fume needs downdraft extraction or filtration; loud | Enclosed or semi-enclosed, extraction still required; quieter |
| Capital cost | Lowest; the duct-shop default | Higher; falling every year, still a multiple of a plasma table |
| Floor, power and air | Three-phase, compressed air, extraction | Three-phase with stable supply, clean dry assist gas, chiller, extraction |
| Operator skill | Low; consumable changes and height control are the learning curve | Low to moderate; focus, gas and lens care |
| Software | Standard CAM output (CAMduct, PractiCAM, FabShop or cut lists) through a plasma post | Same nesting, laser post; no kerf compensation to speak of |
Brand and product names are the property of their respective owners, referenced here for honest comparison only. Ownership, positioning and published ranges are as verified in September 2026 from each maker’s own publications; confirm current specifications and support with each vendor before buying.
Which shop buys which
- Galvanised commercial duct, seamed fittings, one shift: plasma. The dross is inside a seam or under a flange; nobody sees it. The capital saving funds the coil line or the TDF former you need more.
- Stainless kitchen exhaust, marine, pharmaceutical or food duct: laser. Plasma dross on stainless means deburring every part and a visible heat tint on exposed duct; a laser removes both jobs.
- Aluminium duct and fine fittings: laser. Plasma on aluminium is workable but rough; a laser gives clean edges and accurate small holes for take-offs and dampers.
- Mixed shop cutting plate as well as duct: a bigger plasma source (85–125 A) or a 3 kW laser, depending on plate thickness; above about 8 mm, plasma wins on cost.
- High volume, two shifts, labour-constrained: laser, because near-zero consumables and no deburring change the cost per part more than the capital cost changes the monthly payment. Run the numbers in our payback calculator.
- Both: larger shops keep a plasma for galvanised blanks and plate and a laser for stainless, aluminium and fine fittings. The two share the same nesting software.
The worked example: Taokron SBPC plasma and SBLC laser
This is our own equipment, so read it as a vendor’s example. The SBPC plasma table comes in 1550×4000 and 1550×5000 mm beds sized to 1250 and 1550 mm coil-fed blanks, cuts 0.4–4 mm at 7–8 m/min on a 12 kW draw, and weighs 1,500–2,300 kg. The SBLC fiber laser comes as SBLC-4015/2000 (2 kW, 0.5–6 mm) and SBLC-4015/3000 (3 kW, 0.8–8 mm) on a 1500×4000 mm bed, 3,000–3,500 kg. Both take standard cut lists and nesting output from the CAM you already run, and both are sold with the coil line, TDF former and welders, commissioned by one team. Ask us for the cost-per-part comparison on your own fitting nest; we will show the plasma consumable cost against the laser gas and power cost at your volumes rather than argue in the abstract. Other makers’ plasma tables are compared in our HVAC plasma table guide.
Before you sign, for either table
- Cut your own fitting nest at your usual gauge and the heaviest, and measure it against the drawing. Put it in the factory acceptance test.
- Confirm consumables (plasma) or assist gas and lens (laser) supply and price in your country.
- Confirm the software path with a real job file.
- Size the bed to the blanks your line produces, not to the sheet you buy today.
- Budget extraction; zinc fume is not optional either way.
Ask for a plasma-versus-laser cost per part on your nest →
FAQ
Can a fiber laser cut galvanised duct sheet?
Yes. Modern fiber lasers cut galvanised steel cleanly at duct gauges; the zinc coating produces fume that needs extraction, as it does with plasma. The edge is dross-free, so no deburring.
Is plasma good enough for HVAC duct fittings?
For galvanised commercial duct, yes; it is the industry default. Slight dross and heat tint sit inside seams and under flanges. Plasma struggles on stainless and aluminium, where the edge needs deburring.
Which is cheaper to run?
Per part at duct gauges, the laser: near-zero consumables and no deburring against plasma torch sets that wear with every pierce. Per month, the plasma: lower capital cost. The crossover depends on pierces per shift and how much stainless or aluminium you cut.
What laser power does a duct shop need?
2 kW covers 0.5 to 6 mm and every duct gauge with margin; 3 kW reaches 8 mm for shops that also cut plate. More power buys thickness, not duct-gauge quality.
Can one shop run both?
Yes, and larger shops do: plasma for galvanised blanks and plate, laser for stainless, aluminium and fine fittings, sharing one nesting software.
Does Taokron sell both?
Yes: the SBPC plasma table (1550 x 4000 or 5000 mm, 0.4 to 4 mm) and the SBLC fiber laser (1500 x 4000 mm, 2 or 3 kW), both with the duct line and one commissioning team.
