Tube and Profile Laser Cutting
Tube laser cutting rotates and feeds tube or profile through a laser head, cutting holes, slots and joint geometry along its length.
- Part
- Cutting
- Revised
- 2026-08-11
At a glance
- Family
- Thermal
- Typical tolerances
- ±0.005 in (±0.13 mm) on feature position within a setup; roughly ±0.020 in (±0.5 mm) cumulative over multi-meter lengths; overall accuracy is also bounded by the mill tolerance of the incoming tube
- Surface finish
- Edge quality follows ISO 9013 thermal cut classification; nitrogen-cut stainless is bright and weld-ready, oxygen-cut mild steel carries an oxide layer
- Typical volumes
- 10–50,000 parts; bundle loading makes production runs efficient
- Lead time
- 3–10 business days; production runs quote by the bar
- Materials
- Metal
What it is
Tube laser cutting feeds round, square, rectangular or structural profile through chucks that rotate and advance it under a laser head, cutting holes, slots, copes, miters and joint geometry anywhere along its length. One operation replaces the whole sequence of saw, drill, mill, notch and jig, working directly from a 3D model.
Common machines take 0.5–6 in (12–150 mm) diameter or across flats, with large machines reaching 10–12 in (250–300 mm), fed from bars typically 20–27 ft (6–8 m) long. Wall thickness capacity on typical machines runs to about 0.5 in (12 mm) in steel.
The real payoff is tab-and-slot joinery. Features cut into mating tubes locate the assembly without a weld fixture, and the money saved in the weld shop usually exceeds the cost of the cutting.
How it works
- Bulk loading. A bundle loader feeds full-length bars into the machine automatically, which is what makes the process economic on production runs rather than one-offs.
- Chucking and rotation. Self-centering chucks grip the profile and rotate it under the head while a feed system advances it along its axis. On square and rectangular section, the machine indexes face to face.
- Profile measurement. Better machines measure the actual section before cutting to correct for the twist, seam position and dimensional variation that mill-supplied tube always carries. This matters because the laser cannot cut more accurately than the tube it is given.
- Programming from the 3D model. CAM wraps 2D features onto the curved or faceted surface and generates the intersection curves for copes and miters directly from the assembly geometry.
- Cutting. A 2D head cuts perpendicular to the surface; a 3D or 5-axis head tilts to cut bevels up to about 45° for weld preparation and to keep the beam normal to the wall around the corner radii of square section.
- Assist gas. The same rules as flat sheet: oxygen on mild steel for speed with an oxide edge, nitrogen on stainless and aluminum for a bright, weld-ready edge.
- Slug management and unloading. Slugs from internal cutouts drop inside the tube and must be able to escape, or they rattle around in the finished weldment. Finished parts are unloaded and the remnant is ejected.
Design guidelines
Design tab-and-slot joints
This is the reason to use the process. Cut a tab on one member and a matching slot in the other so the weldment self-locates and self-squares. Allow 0.004–0.010 in (0.1–0.25 mm) of clearance per side — tight enough to locate, loose enough to assemble with mill tolerance on the tube.
Understand where the tolerance actually comes from
Feature-to-feature position within one setup holds around ±0.005 in (±0.13 mm), but over a multi-meter part cumulative length is looser, realistically ±0.020 in (±0.5 mm). More importantly, the raw tube is only held to mill tolerance on OD, wall and straightness, and no laser can improve on that. If a dimension is critical, dimension it from a cut feature, not from the tube's own surface.
Account for the weld seam
Welded (ERW) tube carries an internal bead that can foul close-fitting inserts and shifts wall thickness locally. If features must clear it, specify seam orientation on the print or call out DOM or seamless tube.
Apply the flat-sheet feature rules to the wall
Minimum hole diameter about 1× wall thickness (1.5× in stainless), minimum slot width 1× wall, and minimum web between features 1× wall. On square and rectangular section, keep features off the corner radii, which typically run 1.5–2.5× wall thickness on structural tube.
Leave slugs a way out
Internal cutouts drop slugs inside the tube. Either provide an opening they can exit through, or accept that they will be tack-held by micro-tabs and removed manually.
Use the bevel capability for weld prep
A 3D head cuts weld bevels up to about 45° in the same operation, eliminating a grinding step on structural joints.
| Profile / material | Suitability | Notes |
|---|---|---|
| Round tube, mild steel | Excellent | The core application; copes and miters cut directly |
| Square and rectangular tube | Excellent | Machine indexes face to face; avoid features on corner radii |
| Angle, channel, flat bar | Good | Open sections need support against twist |
| I-beam and structural section | Machine dependent | Large-format machines only; confirm capacity first |
| Stainless tube | Good | Nitrogen assist for a bright, weld-ready edge |
| Aluminum tube | Good | Slower than steel; dross on the inside wall |
| Very thin wall under 0.040 in (1 mm) | Marginal | Distortion and part collapse under chuck pressure |
| Feature | Recommended | Limit | Why |
|---|---|---|---|
| Tube diameter | 1–6 in (25–150 mm) | 0.5–12 in (12–300 mm) | Machine chuck capacity |
| Wall thickness | 0.06–0.25 in (1.5–6 mm) | ~0.5 in (12 mm) | Laser power and edge quality |
| Hole diameter | ≥ 1.5× wall | 1× wall | Pierce quality on a curved surface |
| Tab-to-slot clearance | 0.004–0.010 in (0.1–0.25 mm) | 0.002 in (0.05 mm) | Mill tolerance on the tube itself |
| Feature to tube end | ≥ 1× wall thickness | — | Edge distortion at the cut end |
| Bevel angle | ≤ 45° | Head dependent | 3D head tilt range |
Cost drivers
Tube laser competes not against another cutting process but against an entire fabrication sequence, and that is how it should be priced.
Operations eliminated. A bracket that would have taken a saw cut, two drilling setups, a notching operation and a weld fixture becomes one machine cycle. Compare total delivered cost, not cost per cut.
Cut length and pierce count. As on flat sheet, every hole is a pierce plus a contour, and pierce time grows with wall thickness.
Material utilization. You buy full bars. A part length that divides evenly into a 20–24 ft bar leaves almost no remnant; one that divides badly wastes several feet per bar.
Setup and profile changes. Changing section size or shape means re-chucking and re-proving. Grouping parts of the same section into one run matters.
Weld fixture avoided. Tab-and-slot geometry can remove a welding fixture entirely, which on a low-to-mid volume weldment is often the single largest saving.
Four ways to take cost out:
- Design self-locating tab-and-slot joints so no weld fixture is needed.
- Choose a part length that nests cleanly into standard 20–24 ft bar.
- Standardize on one or two tube sections across the assembly to avoid setup changes.
- Cut weld bevels on the machine instead of grinding them afterward.
Questions
6 questionsWhat size tube can a tube laser cut?
Common machines handle 0.5–6 in (12–150 mm) diameter or across flats, with large-format machines reaching 10–12 in (250–300 mm). Wall thickness capacity is typically up to about 0.5 in (12 mm) in steel. Bars are usually fed at 20–27 ft (6–8 m) lengths from an automatic bundle loader.
What tolerance does tube laser cutting hold?
About ±0.005 in (±0.13 mm) on feature position within one setup, opening to roughly ±0.020 in (±0.5 mm) cumulatively over a multi-meter part. The bigger constraint is that the raw tube is only held to mill tolerance on OD, wall and straightness, and the laser cannot improve on the section it is given.
What are tab-and-slot joints and why do they matter?
They are interlocking features cut into mating tubes so the weldment locates and squares itself without a fixture. Allow 0.004–0.010 in (0.1–0.25 mm) of clearance per side. On low and mid volume weldments, eliminating the weld fixture is usually a larger saving than the cost of the laser cutting itself.
Does the weld seam in ERW tube cause problems?
It can. Welded tube carries an internal bead that fouls close-fitting inserts and locally changes the effective wall. If features must clear it, specify seam orientation on the drawing or call out DOM or seamless tube instead. Better machines also measure the actual section before cutting to correct for seam position and twist.
Can a tube laser cut bevels for welding?
Yes, on machines with a 3D or 5-axis head, typically up to about 45°. Cutting the weld preparation in the same operation removes a separate grinding step, which is a meaningful saving on structural joints where every member needs prep.
When is sawing still the better choice?
When the part is a plain length with no features. A saw cut is far cheaper per piece than a laser cycle, and tube laser earns its cost through features, copes and joint geometry. Once a part needs holes, notches or a coped end, the laser usually wins on total cost.