Every extruded rectangular tube is pushed through a hollow (porthole) die made for its exact width, height and wall, so the sizes that already have tooling are the fastest and cheapest to buy. This guide lists common sharp-corner rectangular and square tube sizes with their weight per metre, explains when a new die is needed, and sets out the design rules, alloys, tolerances and finishes that apply to custom rectangular tube.
Rectangular tube is a hollow extrusion, so it needs a two-part porthole die: a mandrel that forms the inside and a die plate that forms the outside. The die is machined from hot-work tool steel for one specific section, and its cost and trial time are the main reasons a custom size takes longer than a standard one.
Hundreds of rectangular sizes already have tooling in the extrusion supply chain because they are used every day in frames, furniture, machinery, vehicles and buildings. Choosing one of those sizes means no tooling charge, no die trial and a proven section that the press runs consistently. When a design truly needs a different size, wall or corner shape, a new die is made and the tube is produced from your drawing.
This page is a practical reference. The tables give standard sharp-corner rectangular and square sizes with calculated weights; the later sections explain how dies are designed, which features need new tooling, and how to specify a custom section so that it extrudes well the first time.
A heated aluminium billet is pushed into the die under high pressure. The metal divides into several streams as it flows through ports around the mandrel support bridges, then re-joins in a welding chamber before it passes through the gap between mandrel and die plate. That gap is the tube wall.
Where the streams re-join, solid-state seams form along the tube length. In a correctly run die they are as strong as the parent metal and invisible after finishing, but they are why porthole tube is not treated as "seamless" pipe for code pressure parts.
The land that controls metal speed. Die makers vary bearing length around the section so thick and thin parts of the profile exit at the same speed, which keeps the tube straight and the walls flat.
Sharp outside corners are standard on architectural tube, typically with a small internal radius. Rounded-corner tube needs different tooling and has a specified outside radius.
The circumscribing circle diameter (CCD), the smallest circle that encloses the section, decides the die and press size. A 100 × 45 mm tube has a CCD of about 110 mm.
Dies wear and are periodically re-nitrided or corrected. A die in regular use is a known quantity; a new die needs a trial and sometimes correction runs.
Small tubes are often run two or more at a time from one die, improving output and price for small sections.
A = width, B = height, T = wall thickness, all in millimetres. Weights are calculated for sharp outside corners and a density of 2.70 g/cm³ (6063, 6061, 6082); real tubes with small internal radii weigh very slightly more. Inch sizes such as 25.4 × 12.7 mm (1 × 1/2 in) and 76.2 × 50.8 mm (3 × 2 in) are included.
| A × B (mm) | Wall T (mm) | kg per metre | kg per 6 m length |
|---|---|---|---|
| 12 × 10 | 1 | 0.108 | 0.65 |
| 18 × 12 | 1.4 | 0.206 | 1.23 |
| 20 × 10 | 1 | 0.151 | 0.91 |
| 20 × 10 | 1.5 | 0.219 | 1.31 |
| 20 × 12 | 1 | 0.162 | 0.97 |
| 20 × 12 | 1.5 | 0.235 | 1.41 |
| 20 × 15 | 1 | 0.178 | 1.07 |
| 25 × 15 | 1 | 0.205 | 1.23 |
| 25 × 15 | 1.5 | 0.300 | 1.80 |
| 25 × 15 | 1.8 | 0.354 | 2.12 |
| 25 × 20 | 1.2 | 0.276 | 1.66 |
| 25 × 20 | 1.5 | 0.340 | 2.04 |
| 25.4 × 12.7 | 1 | 0.195 | 1.17 |
| 30 × 10 | 0.9 | 0.186 | 1.11 |
| 30 × 15 | 1 | 0.232 | 1.39 |
| 30 × 15 | 1.5 | 0.340 | 2.04 |
| 30 × 15 | 2 | 0.443 | 2.66 |
| 30 × 20 | 2 | 0.497 | 2.98 |
| 30 × 20 | 3 | 0.713 | 4.28 |
| 30 × 25 | 1 | 0.286 | 1.72 |
| 34 × 20 | 2 | 0.540 | 3.24 |
| 34 × 20 | 3 | 0.778 | 4.67 |
| 35 × 25 | 1.5 | 0.462 | 2.77 |
| 35 × 25 | 2 | 0.605 | 3.63 |
| 35 × 25 | 4 | 1.123 | 6.74 |
| 38 × 19 | 3 | 0.826 | 4.96 |
| 38 × 25 | 1 | 0.329 | 1.98 |
| 38.1 × 25.4 | 1 | 0.332 | 1.99 |
| 40 × 12 | 2 | 0.518 | 3.11 |
| 40 × 15 | 2 | 0.551 | 3.30 |
| 40 × 20 | 1.2 | 0.373 | 2.24 |
| 40 × 20 | 2 | 0.605 | 3.63 |
| 40 × 20 | 3 | 0.875 | 5.25 |
| 40 × 25 | 1 | 0.340 | 2.04 |
| 40 × 25 | 2 | 0.659 | 3.95 |
| 40 × 25 | 3 | 0.956 | 5.73 |
| 40 × 30 | 1.5 | 0.543 | 3.26 |
| 40 × 30 | 2 | 0.713 | 4.28 |
| 45 × 20 | 1.4 | 0.470 | 2.82 |
| 50 × 20 | 1 | 0.367 | 2.20 |
| 50 × 20 | 2 | 0.713 | 4.28 |
| 50 × 25 | 1.4 | 0.546 | 3.27 |
| 50 × 25 | 2 | 0.767 | 4.60 |
| 50 × 25 | 3 | 1.118 | 6.71 |
| 50 × 30 | 1.2 | 0.503 | 3.02 |
| 50 × 30 | 2 | 0.821 | 4.92 |
| 50 × 30 | 3 | 1.199 | 7.19 |
| 50 × 30 | 4 | 1.555 | 9.33 |
| 50 × 40 | 1.5 | 0.705 | 4.23 |
| 50 × 40 | 2 | 0.929 | 5.57 |
| 50.8 × 25.4 | 1.4 | 0.555 | 3.33 |
| 50.8 × 25.4 | 3.18 | 1.199 | 7.20 |
| 50.8 × 38.1 | 2 | 0.917 | 5.50 |
| 55 × 30 | 2 | 0.875 | 5.25 |
| 60 × 20 | 1.4 | 0.584 | 3.50 |
| 60 × 20 | 2 | 0.821 | 4.92 |
| 60 × 30 | 1.5 | 0.705 | 4.23 |
| 60 × 30 | 2 | 0.929 | 5.57 |
| 60 × 40 | 2 | 1.037 | 6.22 |
| 60 × 40 | 3 | 1.523 | 9.14 |
| 60 × 40 | 4 | 1.987 | 11.92 |
| 60 × 50 | 3 | 1.685 | 10.11 |
| 63.5 × 38.1 | 3.18 | 1.635 | 9.81 |
| 65 × 30 | 1.6 | 0.793 | 4.76 |
| 70 × 30 | 1.5 | 0.786 | 4.71 |
| 70 × 50 | 3 | 1.847 | 11.08 |
| 75 × 25 | 2 | 1.037 | 6.22 |
| 75 × 50 | 1.4 | 0.924 | 5.54 |
| 76.2 × 25.4 | 3.18 | 1.635 | 9.81 |
| 76.2 × 38.1 | 1.4 | 0.843 | 5.06 |
| 76.2 × 50.8 | 3.18 | 2.072 | 12.43 |
| 76.2 × 50.8 | 4.5 | 2.867 | 17.20 |
| 80 × 20 | 2 | 1.037 | 6.22 |
| 80 × 30 | 2 | 1.145 | 6.87 |
| 80 × 40 | 1.5 | 0.948 | 5.69 |
| 80 × 40 | 3 | 1.847 | 11.08 |
| 80 × 40 | 4 | 2.419 | 14.52 |
| 80 × 50 | 4 | 2.635 | 15.81 |
| 80 × 60 | 2 | 1.469 | 8.81 |
| 80 × 60 | 3 | 2.171 | 13.02 |
| 80 × 70 | 6 | 4.471 | 26.83 |
| 100 × 30 | 2 | 1.361 | 8.16 |
| 100 × 30 | 3 | 2.009 | 12.05 |
| 100 × 40 | 2 | 1.469 | 8.81 |
| 100 × 40 | 3 | 2.171 | 13.02 |
| 100 × 44 | 2 | 1.512 | 9.07 |
| 100 × 45 | 3 | 2.252 | 13.51 |
Calculated weights for reference. For any size not listed, use the rectangular tube weight calculator: mass (kg/m) = 2 × T × (A + B − 2T) × 0.0027.
Square tube uses the same porthole tooling principle. Thick-wall square sections, with walls of 6 – 10 mm and more, are used for machine frames, robot arms and parts that are machined after extrusion.
| Size (mm) | Wall T (mm) | kg per metre | Typical use |
|---|---|---|---|
| 19.05 × 19.05 | 3.2 | 0.548 | Thick-wall, machined parts |
| 25 × 25 | 2 | 0.497 | Light frames, furniture |
| 25.4 × 25.4 | 3 | 0.726 | Thick-wall, machined parts |
| 30 × 30 | 2 | 0.605 | Light frames, furniture |
| 32 × 32 | 4 | 1.210 | Thick-wall, machined parts |
| 40 × 40 | 3 | 1.199 | Structural frames |
| 45 × 45 | 5 | 2.160 | Thick-wall, machined parts |
| 50 × 50 | 3 | 1.523 | Structural frames |
| 50 × 50 | 4 | 1.987 | Structural frames |
| 50.8 × 50.8 | 3 | 1.549 | Structural frames |
| 60 × 60 | 4 | 2.419 | Structural frames |
| 60 × 60 | 6 | 3.499 | Thick-wall, machined parts |
| 70 × 70 | 5 | 3.510 | Structural frames |
| 90 × 90 | 9 | 7.873 | Thick-wall, machined parts |
| 100 × 100 | 3 | 3.143 | Structural frames |
| 100 × 100 | 6 | 6.091 | Structural frames |
| 100 × 100 | 10 | 9.720 | Thick-wall, machined parts |
See the separate square tube mould guide for a longer list of square sizes, and the extra-large square and rectangular tube page for sections over 300 mm.
| Variant | Example sizes | Features | Typical uses |
|---|---|---|---|
| Rounded-corner (radiused) | 20 × 40 × 2, 30 × 60 × 3, 50 × 100 × 4 mm with R2 – R10 | Soft outside corners, safer to handle, coat more evenly | Roof racks, ladders, furniture, handrails |
| Flat-oval / obround | 20 × 40, 30 × 60 mm | Fully rounded short sides | Seating, trolleys, fluid lines |
| Slim thin-wall | 15 × 40 × 1.0, 20 × 50 × 1.2, 30 × 60 × 1.5 mm | Walls down to about 0.8 – 1.2 mm; width-to-height up to about 4 : 1 | Display frames, LED housings, interiors |
| Thick-wall | 50 × 80 × 6, 60 × 100 × 8, 80 × 120 × 10 mm | Walls of 5 – 12 mm and more | Vehicle frames, heavy equipment, machined parts |
| Multi-cavity and ribbed | To drawing | Internal webs add stiffness or form separate channels | Battery trays, platforms, cooling and cable ducts |
| Telescopic sets | Nested sizes with controlled clearance | Outside of one tube slides inside the next | Adjustable legs, poles, booms |
Rounded corners, internal ribs, non-90° walls and any section outside the listed sizes need their own die. For telescoping sets, the clearance is set by the tolerance stack of both tubes, so it is worth checking the combination with us before ordering; see square telescopic tubes.
| Situation | New die needed? | What happens |
|---|---|---|
| Size, wall and corner match an existing die | No | Produced directly; no tooling charge |
| Same outside size but a different wall | Usually yes | A new mandrel or complete die is cut, since the wall gap is fixed by the tooling |
| Size from your own drawing, not in the existing range | Yes | Die designed from the drawing, trial-extruded and measured before production |
| Double or multi-cavity, ribs, non-90° walls | Yes | More complex porthole die; extrudability review recommended |
| Special corner radius or tight precision tolerances | Yes | New die plus possible post-extrusion sizing or machining |
| Rectangular tube cut, drilled or bent to drawing | No | Produced from a standard die, then processed |
| Alloy and temper | Min. tensile (MPa) | Min. yield (MPa) | Best for |
|---|---|---|---|
| 6063-T5 | 150 | 110 | Architectural, furniture, display frames, anodised parts |
| 6063-T6 | 205 | 170 | General frames needing more strength |
| 6061-T6 | 260 | 240 | Structural and machine frames, welded assemblies |
| 6005A-T6 | Between 6063-T6 and 6082-T6 | Thin-wall structural tube with good extrudability | |
| 6082-T6 | Highest of the 6xxx group in thicker walls | European structural and transport applications |
6063 and 6061 minimums from ASTM B221 for extruded tube; EN 755-2 minimums apply to EN orders and vary with wall thickness.
No. If the width, height, wall and corner style match an existing die, the tube is produced directly with no tooling charge. A tooling cost applies only when a new die has to be made.
Generally not. The wall is the gap between mandrel and die plate, so a different wall needs a new mandrel or a new die. Ask us, because a nearby existing size may meet your load requirement.
No. It is made in a porthole die, which forms longitudinal seam welds where metal streams re-join. They are sound for structural and general use, but code pressure piping normally requires seamless tube made over a mandrel.
6063-T5 or T6 for architectural, furniture and anodised parts; 6061-T6 for structural frames and welded assemblies; 6005A or 6082 for thin-wall structural sections and European specifications.
Multiply 2 × wall × (width + height − 2 × wall), all in mm, by 0.0027 to get kg per metre. For example, 50 × 25 × 2 mm tube weighs about 0.77 kg/m.
EN 755-9 for general profiles, EN 12020-2 for precision 6060/6063 sections, and ANSI H35.2 for orders to ASTM B221. Tighter tolerances can be agreed for a custom die.
Send the dimensions or drawing, alloy, finish and quantity. We will check existing tooling and reply with a price and delivery.
