Nesting software for plasma cutting

Most nesting software is built with laser cutting in mind, and the assumptions travel badly. Plasma kerf is typically 0.06 to 0.16 in (1.5 to 4 mm) depending on plate thickness, amperage and gas, against 0.004 to 0.012 in (0.1 to 0.3 mm) for a fiber laser on the same steel. A layout that treats cut width as a rounding error hands back parts that measure short, and it does it to every part on the plate at once.

Heat is the second difference. A plasma cut leaves a heat-affected zone running back from the edge, and two cuts close together heat the web between them twice, so common practice is to hold minimum part spacing 0.08 to 0.2 in (2 to 5 mm) beyond kerf rather than packing parts as tightly as the geometry allows.

Third is thickness. Plasma runs from about 0.15 in (4 mm) plate up past 2 in (50 mm), so lead-ins and lead-outs need real clearance outside the part profile, and a nest packed without room for them produces a layout the CAM step cannot post cleanly.

Measure kerf as the cut width on your own table with your own consumables, not a figure off a chart: it moves with amperage, gas, tip wear and thickness. A Hypertherm Powermax hand system, a Langmuir CrossFire table and a Torchmate will each give you a different number on the same plate, and so will the same machine with a worn tip. Lapas places parts by part spacing, so set part spacing to cover your kerf and the heat clearance on top of it, a 0.12 in (3 mm) kerf and 0.08 in (2 mm) of clearance for example, and inch values go in as decimals. There is more on what kerf is and on how part spacing changes a layout.

Pierce count is the number plate shops watch that laser shops mostly do not. Every pierce costs consumable life and cycle time, and on thick plate it is the hardest moment of the cut. That is why common-line cutting is worth more on a plasma table than on a laser, and why small holes depend on lead-in placement as much as on the layout.

Plate size is set per job, in inches or millimetres, so you enter it the way the rack is labelled: 48 x 96 in (1,219 x 2,438 mm) for a standard 4 x 8 ft plate, 60 x 120 in (1,524 x 3,048 mm) for a 5 x 10, and a drop is simply a smaller plate. That means the same parts can be nested against a remnant first to see whether the job fits before a full plate is committed. Remnant management is where most of the recoverable material in a plate shop sits, and Lapas keeps remnants in their real shape on every plan.

The files are different too. DXF out of structural steel CAD carries block references, splines, ellipses, detailing layers and duplicated outlines that a nester has to read correctly before it can place anything. Lapas imports DXF, DWG, SVG, vector PDF, Illustrator and LightBurn files and nests true shape, so brackets, gussets and flanged parts interlock instead of being treated as rectangles. When a file still refuses to import, the DXF troubleshooting guide has the causes.

1. Upload the DXF parts in the browser and set quantities, then set plate size and part spacing in inches or millimetres: a 48 x 96 in (1,219 x 2,438 mm) plate of 1/4 in (6.35 mm) A36, spacing set to cover the 0.09 in kerf you measured plus 0.08 in of heat clearance.
2. Run the nest and watch parts place live. Drag or rotate anything the automatic layout put in the wrong place, and the export reflects the edit.
3. Export the layout as DXF for your plasma CAM, and take the PDF report for the quote: plate count, utilization and the part list.

DXF into the CAM you already run is the production path, whether that is SheetCAM or Fusion 360 posting for a Hypertherm Powermax, a Langmuir CrossFire or a Torchmate. Lapas does not talk to any of them and there is nothing to install: it writes the DXF those tools read. G-code export is available on both plans for simple 2-axis work, but the output has not been validated across controllers and machines, so check it before you cut. Nesting and re-nesting are unlimited on the free plan, with no cap on parts per job, so a real file can be run again and again until the layout is right. The plan includes 5 project exports a month in any format, and re-exporting a project you have already exported is free for 7 days. Pricing covers the Pro plan, which removes the export cap.

The engine is measured rather than described. Lapas Core v1.1 ran against deepnest-next v1.5.6 over 37 cases, scored by an independent program that recomputes every number from the output geometry. On the 10 ESICUP academic instances Lapas Core averages 86.1% packing density against 73.3%; across 10 sheet-metal jobs it uses 25 plates against 28, and reaches a tighter nest in 10 seconds than Deepnest reaches in 5 minutes. On 7 of those 10 jobs the two tie on plate count. The full run is on the benchmark page. Against hand nesting: most shops see 15-30% better utilization vs. manual nesting, and typical results vary by job type and current method.

Deepnest is free, open source and offline, and the community deepnest-next fork shipped v1.5.6 in May 2025 and is actively maintained, while the original stopped at v1.0.5 in 2021 (full comparison). ProNest LT wins outright on Hypertherm hardware, because SureCut is tied to their machines. It is Windows only, and the entry plan, Smart Start, was $29.99 per month per user with a 7 day trial on Hypertherm's subscription pages when we checked in July 2026 (full comparison). SigmaNEST is the enterprise option, Windows desktop with quote-only pricing as of July 2026, covering post processors, scheduling and ERP integration that Lapas does not touch (full comparison).