Extrusion from die to delivery
Aluminum Profiles — Custom Extrusion from Die Design to Delivery
An aluminium profile is a length of extruded aluminium whose cross-section stays the same for the whole run. Heated billet is pushed through a steel die, and the shape of the die is the shape of the profile. That one fact sets most of the commercial rules around the product: the die is a one-off cost, the cross-section cannot be changed mid-run, and the minimum order is decided by how much metal has to pass through the die to justify setting it up. This page walks the buying decisions in the order they actually arise — section, alloy, tolerance, cut length, finish, inspection and packing.
Made to order
Products in this category
No catalogue item is published under this heading yet — the sections below describe the range we manufacture and how it is specified. Send the drawing or the section size you need and we will quote it as a made-to-order item.
Browse the complete product index →An aluminium profile is produced by heating an aluminium billet to roughly 470–500 °C and forcing it through a hardened steel die under a hydraulic press. The die determines the cross-section, and that cross-section is identical from the first metre to the last. Anything you need that the die does not produce — a hole, a thread, a notch, a shorter length — has to be added afterwards as a secondary operation.
So the buying decisions come in a fixed order: which section, in which alloy and temper, to which tolerance, cut to what length, in which finish, and with what machining. Get those six right and the profile arrives ready to assemble. Get one wrong and it is discovered at the joint.
Catalogue section or a new die
Every project starts with the same fork. A catalogue section costs nothing to tool and can ship in days. A new die costs a tooling fee and adds roughly two to three weeks to the first delivery, after which the profile belongs to the project and is not normally sold to anyone else.
The break-even is not a quantity, it is a shape. A new die earns its cost when no existing section comes close — a mounting flange in the wrong place, a cable channel that has to run inside the section, a visible face that must be a specific width, or a snap-fit detail that carries the whole design. If a catalogue section is within a few millimetres of what you need, redesigning around it is almost always cheaper than tooling.
Practical point: the die is quoted once but it stays. Repeat orders run against the same tool with no further tooling charge, which is why a custom section gets cheaper per metre the longer a programme runs. Ask for the die to be held in your name if the project is expected to last more than a year.
Alloy and temper: the two decisions behind every profile
The alloy decides how easily the metal flows through the die and how much the finished section can carry. 6063 is the workhorse — it extrudes into complex shapes with thin walls and takes a clean anodised finish, which is why almost every framing profile is 6063. 6061, 6005A and 6082 are harder, carry more load, and are chosen where the section is also a structural member rather than a frame rail.
| Alloy / temper | Extrudability | Typical yield strength | Where it is used |
|---|---|---|---|
| 6063-T5 | Excellent | approx. 145 MPa | General framing, guards, covers, heatsinks |
| 6063-T6 | Excellent | approx. 205 MPa | Framing that also carries load or takes threads |
| 6005A-T6 | Good | approx. 260 MPa | Structural framing, rail and vehicle work |
| 6061-T6 | Moderate | approx. 275 MPa | Structural members and heavily machined profiles |
| 6082-T6 | Moderate | approx. 310 MPa | High-load structural sections and brackets |
Temper is the heat treatment applied after extrusion. T5 is cooled and artificially aged without further deformation: cheaper, and adequate for most framing. T6 is solution-treated and aged to a higher strength, and it is what you specify when the profile will be machined heavily, tapped, or used as part of a load path. The strength step from 6063-T5 to 6063-T6 is roughly 40 %, and the cost step is small, so T6 is often the safer default whenever a section looks marginal. Alloy behaviour is examined in more depth on industrial aluminium profiles: alloys and tempers.
Tolerance: what the standard allows and what you must call out
Extrusion tolerance is governed by standards such as EN 755-9 and GB/T 6892, and the allowance scales with the size of the dimension. A 20 mm dimension and a 200 mm dimension on the same profile do not receive the same tolerance, which is why a drawing that only carries a general note is not enough to inspect against.
| Dimension | Typical allowance | What it controls |
|---|---|---|
| Wall thickness | ±5 % of nominal, min ±0.10 mm | Weight, stiffness and available thread depth |
| Slot or groove width | ±0.10 mm | Nut fit and connector engagement |
| Overall width and height | ±0.15 mm to 40 mm, scaling above | Stack-up in multi-member frames |
| Twist | ≤1° per metre | How flat a long member sits against a panel |
| Straightness | ≤1.5 mm per metre | Gaps at joints and panel flatness |
| Cut length | ±0.3 mm when cut to list | Whether the frame closes square |
Two dimensions deserve to be stated explicitly on any profile drawing: wall thickness, because it drives both weight and stiffness, and straightness, because a bowed profile shows up as a gap at every joint in a long frame. Critical features — a slot width, a bore, a mating face — should be individually toleranced rather than left to the general note. The inspection side of this is set out on aluminium extrusion tolerance and inspection plans.
Cut length, end work and machining
Profiles are supplied as mill lengths, normally 3 to 6 metres, or cut to a cut list. Cut-to-length is worth paying for whenever the buyer has no saw: it removes a second operation, guarantees square ends and keeps a long frame dimensionally consistent. Where the frame is supplied as a kit we mark each member to the cut list so it can be assembled without re-measuring.
- Cutting — to ±0.3 mm on length, ends square and deburred, chamfered where the end face is visible.
- Drilling and tapping — end taps, cross holes, counterbores and thread inserts, including threads that must survive repeated assembly.
- Milling and notching — machining a slot flat, cutting a notch for a cross member, or milling a face to a datum.
- Punching — the cheapest way to put a repeated hole pattern into a long run, where drilling would be slower and less consistent.
Doing this work at the extrusion stage instead of in the customer's workshop avoids a second setup and stops tolerance stack-ups accumulating across two suppliers. The full capability list is on CNC machining.
Surface finish
Mill finish is bare extruded aluminium: cheapest, and correct when the profile will be painted or hidden inside an assembly. Anodising is the default for anything visible or handled, because the oxide layer is grown from the metal itself and cannot chip away at a slot edge the way a coating can. Natural, black and bronze are held as standard; the process and its dimensional effect are described on anodised aluminium profiles.
Powder coating is specified when a particular RAL colour has to be matched or when the profile sits outdoors in a coloured structure. It is a thicker film than anodising, so sliding joints need slightly more clearance. Brushed and polished finishes are used mainly for visible architectural and display work.
Inspection, packing and what protects the profile in transit
Incoming billet is checked for alloy and hardness, and each run is inspected against the drawing for cross-section, wall thickness, straightness, twist, length and finish. Where a project is large or the profile is safety-related, a first-article report with measured dimensions is issued before the run is released.
Packing matters more than most buyers expect, because a scratched profile is a rejected profile. Standard export packing is a heat-treated timber or plywood bundle with interleaved protection between profiles, full-length protective film on anodised and coated faces, and corner protection on the bundle ends. Long sections are bundled to suit a 20 ft or 40 ft container. Buyers who want to avoid disputes at the port should read the importing aluminium profiles contract checklist, and buyers who want to know what to verify before placing a first order should read how to audit an aluminium profile supplier.
What decides the price of an aluminium profile
A catalogue section carries no tooling; a new die adds a one-off cost that is recovered over the life of the programme, not the first order.
Harder alloys press more slowly and cost more per kilogram. 6061 and 6082 typically run 10–20 % above 6063.
Mill finish is the baseline. Anodising and powder coating add a per-square-metre charge plus handling, and a thicker anodic film costs more than a thin one.
Every hole, thread and notch is a separate operation. A profile with eight machining features can cost more to finish than to extrude.
How to specify an aluminium profile and get a fast quote
Six items remove almost all of the ambiguity:
- Cross-section — a dimensioned drawing, a 3D model, a physical sample, or the die code if the tool already exists.
- Alloy and temper — for example 6063-T6. If you are unsure, say what the profile has to carry and we will recommend one.
- Tolerance — the standard class, plus any individually toleranced dimensions.
- Length — a cut list, or total metreage as mill lengths.
- Finish — mill, anodised (with film thickness) or powder coated (with RAL number).
- Machining and packing — operations required, and whether the parts must be marked and bagged by assembly.
Send a section drawing or a sketch with the overall envelope and we will confirm the section, the alloy and the commercial terms. Quotes against catalogue sections are normally returned within one working day. Related ranges: strut profiles for slotted framing, aluminium sections for non-slotted shapes, angle profiles and conduit profiles for specific geometries, and the full list on all products.
FAQ
Questions buyers ask about this range
What is the minimum order for a custom aluminium profile?+
The minimum is set by the die, not by the profile. For a catalogue section we run from about 100 m. For a new die the economic batch is normally 300–500 kg per alloy and finish combination, because the press has to be set up and the die brought up to temperature. The die is quoted separately so repeat orders are priced only on metal and processing.
How long does a new die take?+
A simple solid section is typically 12–18 working days from drawing approval to first samples, covering die manufacture, trial extrusion, sample inspection and any correction. Complex hollow sections with multiple cavities can take 20–25 working days. The die then remains available for every repeat order at no further tooling cost.
Which alloy should I choose for a framing profile?+
6063-T6 for almost all framing, guarding and workbench work. Move to 6061-T6 or 6082-T6 when the profile is also a structural member or will be machined heavily. 6005A-T6 sits between the two, with better extrudability than 6061 at close to the same strength.
What tolerance can you hold on an extruded profile?+
Standard tolerances follow EN 755-9 or GB/T 6892 and scale with the size of the dimension. We normally hold wall thickness within ±5 % and slot width within ±0.10 mm, and can work to tighter classes where critical dimensions are individually toleranced on the drawing.
Can you supply profiles cut to a cut list?+
Yes. Send the cut list and we return members cut to ±0.3 mm with square, deburred ends, marked by member number and bagged by assembly. Cut-to-length normally removes a saw operation at your end and keeps long frames square.
Do you machine the profiles as well as extrude them?+
Yes. Drilling, tapping, milling, notching, punching and counterboring are all done in-house, which avoids a second setup and a second set of tolerance stack-ups. The capability list is on CNC machining.
How are profiles packed for sea freight?+
Bundles with interleaved protection, full-length film on finished faces and corner protection on the ends, sized to a 20 ft or 40 ft container. Cut lists are marked and bagged by member, and all timber is heat-treated and ISPM 15 compliant.
What do you need to quote a custom profile?+
A cross-section drawing with critical dimensions, the alloy and temper, the finish, the cut list or total metreage, and any machining operations. A 3D model or a physical sample also works. Quotes against catalogue sections are normally returned within one working day.
Need this range specified for your project?
Send the drawing, the section size or a sample and we will confirm the alloy, the tolerance, the finish and the commercial terms. Quotes for standard items normally go out within one working day.
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