Aluminium Alloy Extrusion Profiles: Complete Classification by Alloy, Shape & Application

Aluminium alloy extrusion profiles are classified by four intersecting systems: alloy composition, profile geometry, temper designation, and end-use application. Understanding these classifications helps buyers specify exactly what they need — and helps suppliers like NA-VIEW quote and produce accurately. With over 500 unique profiles running daily across six extrusion lines, classification is not academic for us — it is how we organise our die library, our production schedules, and our quality documentation.

Classification by Alloy Series

The International Alloy Designation System (IADS) uses a four-digit code to identify wrought aluminium alloys. For extrusion, the 6xxx series (Al-Mg-Si) dominates, but other series appear in specialised applications:

1xxx Series: Pure Aluminium (99.0%+ Al)

Excellent corrosion resistance and electrical conductivity, but low strength (70–100 MPa). Rarely extruded as structural profiles; primarily used for electrical bus bars and heat exchanger tubes where conductivity matters more than strength. NA-VIEW produces 1050 and 1060 bus bar profiles for electrical enclosure manufacturers.

3xxx Series: Al-Mn Alloys

Moderate strength (110–170 MPa) with excellent formability and corrosion resistance. Not commonly extruded due to limited age-hardening response. 3003 and 3103 are occasionally specified for decorative trim and signage profiles where formability is the priority.

5xxx Series: Al-Mg Alloys

High strength (200–350 MPa) and excellent corrosion resistance, but challenging to extrude — high magnesium content increases deformation resistance and causes surface tearing at normal extrusion speeds. 5083 and 5086 are used for marine structural profiles where seawater corrosion resistance is critical. These alloys require reduced extrusion speeds and specialised die coatings, increasing production cost by approximately 30–50% compared to 6063.

6xxx Series: Al-Mg-Si Alloys — The Extrusion Workhorses

This series accounts for over 90% of all aluminium extrusion profiles. The magnesium and silicon combine to form Mg₂Si precipitates that provide age-hardening — the profile gains strength during the artificial aging heat treatment after extrusion.

For a deeper technical comparison of the two most common alloys, see our 6063 vs 6061 aluminium alloy guide.

7xxx Series: Al-Zn Alloys

The highest strength aluminium alloys (500+ MPa), primarily used in aerospace and high-performance sporting goods. 7005 and 7020 are occasionally extruded for bicycle frames and structural aerospace components. These alloys are difficult to extrude and require solution heat treatment plus artificial aging — extrusion speed is only 10–20% of 6063 speed, making them significantly more expensive. NA-VIEW does not routinely stock 7xxx series billets; they are available on special order.

Classification by Profile Geometry

Profile geometry classification directly affects die design, extrusion parameters, and cost:

Solid Profiles

The simplest geometry — a single enclosed boundary. Solid profiles use the simplest (and cheapest) dies and achieve the highest extrusion speeds. Examples: flat bars, angles, channels, T-sections, and simple decorative trim. Approximately 40% of NA-VIEW’s production volume is solid profiles.

Semi-Hollow Profiles

A profile where a partially enclosed area has a tongue ratio (area of partial enclosure divided by square of the gap opening) between 2:1 and 5:1. Semi-hollow profiles require a die with a supported mandrel element, increasing die complexity and cost by approximately 50% compared to solid profiles. Examples: C-channels with return flanges, profiles with deep narrow grooves, and partial box sections.

Hollow Profiles

Any profile with one or more completely enclosed voids. Hollow profiles require a two-part die (die cap + mandrel) — the most complex and expensive die type. The mandrel must be supported by bridge legs that create visible weld lines in the finished profile. Single-hollow profiles (one void) are standard; multi-hollow profiles (2–8 voids) increase die cost roughly 25% per additional void. Examples: rectangular tubes, thermal break profiles, multi-chamber curtain wall sections, and heat sink profiles.

Classification by Temper

Temper designation describes the thermal and mechanical processing applied to the profile after extrusion:

• T1: Cooled from extrusion temperature and naturally aged. Low strength, rarely specified.
• T4: Solution heat-treated and naturally aged. Moderate strength, good formability — typically an intermediate temper before further processing.
• T5: Cooled from extrusion temperature and artificially aged. The standard temper for 6063 architectural and industrial profiles. Achieves approximately 80% of maximum strength with good ductility.
• T6: Solution heat-treated and artificially aged. Maximum strength for the alloy. Requires a separate solution heat treatment furnace, adding cost and 1–2 days to lead time.
• T66: Cooled from extrusion at a controlled rate and artificially aged. Higher strength than T5 without the cost of separate solution heat treatment. Increasingly specified for curtain wall profiles.

Classification by Application

How NA-VIEW’s Classification System Supports Buyers

When you request a quotation from NA-VIEW, we ask for three pieces of information that map directly to this classification system: the alloy specification (e.g., “6063-T5”), the profile geometry description or drawing, and the application category. This allows us to instantly route your enquiry to the correct production team, select the appropriate billet inventory, and generate an accurate quotation within 24 hours for standard profiles.

For custom profiles, our 7-day design review process includes alloy recommendation — if your specified alloy is not optimal for the geometry or application, our engineers will suggest an alternative with justification. This has saved customers from ordering profiles in 6061-T6 when 6063-T6 would have met the strength requirement at 20% lower cost.

Frequently Asked Questions

What is the most commonly used aluminium extrusion alloy?

6063-T5, accounting for approximately 70% of global extrusion production. It offers the best combination of extrudability, surface finish, corrosion resistance, and cost for architectural and general industrial applications.

Can different alloys be mixed in one order?

Yes. NA-VIEW can produce profiles in multiple alloys within a single production order, though minimum quantities apply per alloy-die combination (500 kg per die). Different alloys cannot be mixed within a single production run due to billet changeover requirements.

What classification information do I need when requesting a quotation?

At minimum: alloy grade (e.g., 6063), temper (e.g., T5), profile type (solid/semi-hollow/hollow), approximate cross-section dimensions, surface finish requirement, and estimated annual volume. A profile drawing (DXF/DWG) is preferred but not required for initial budget pricing.

Does NA-VIEW stock standard profile classifications?

We stock standard architectural profiles (window, door, and curtain wall sections) and industrial T-slot profiles (20–60 series). All other profiles are made to order. DIE-custom profiles are manufactured against customer drawings with lead times of 25–35 working days.

What payment and shipping terms are available?

Payment: T/T (30% deposit, 70% before shipment), L/C at sight, PayPal (under $2,000). Shipping: FOB Shenzhen, CIF to port, DDP to door. All shipments include mill test certificates and dimensional inspection reports.