Aluminum Door & Window Profiles: Full Guide

By the Naview Aluminium Technical Team | Updated July 2026

After 20 years of extruding aluminum door and window profiles, the question we hear most often is simple: “We’re making windows and doors — which profile do we actually need?”

It sounds straightforward, yet it breaks into at least five decisions: alloy grade, wall thickness, thermal break or not, surface finish, and opening type. For instance, get one wrong and you end up with failed energy codes, hardware that doesn’t fit, or callbacks from the job site.

Therefore, what follows is what we’ve learned from real orders, real factory-floor problems, and real feedback from fabricators and contractors. No fluff.

Table of Contents

1. What Are Aluminum Door and Window Profiles?
2. Alloy Grades: 6063 vs 6061 vs 6060
3. Thermal Break vs Non-Thermal Break: Not Just Price
4. Profile Series Explained (55, 60, 70, 80, 90)
5. Wall Thickness — Where Suppliers Cut Corners
6. Thermal Break Strips: PA66 vs PVC
7. Surface Treatment Options
8. Opening Types and Sealing Performance
9. 5-Step Profile Selection Framework
10. Standards and Certifications
11. Frequently Asked Questions

1. What Are Aluminum Door and Window Profiles?

Aluminum door and window profiles are extruded cross-sections made from Al-Mg-Si alloys, mostly the 6000 series. In other words, they form the skeleton of the window or door: the frame, sash, mullions, and glazing beads that hold the glass, hardware, and weather seals.

Because the cross-section design controls almost every performance metric — thermal insulation, sound reduction, wind load resistance, water tightness, and hardware compatibility — two windows can look identical from the outside yet perform completely differently underneath.

Aluminum holds over 65% of the global commercial window and door market for solid reasons:

• Strength-to-weight ratio: Aluminum gives you steel-like structural performance at roughly one-third of the weight. Consequently, fabricators can design larger glass areas and slimmer sightlines.
• Corrosion resistance: The natural oxide layer protects against rust — a big advantage over steel in coastal and humid environments.
• Extrudability: Aluminum can be extruded into complex hollow shapes with internal chambers, gasket grooves, and hardware slots that other materials simply cannot form.
• Recyclability: Aluminum profiles can be recycled indefinitely without losing properties. Therefore, they matter for green building certification.
• Finish versatility: Powder coating, anodizing, and wood grain transfer offer hundreds of color options with 20–30 year outdoor durability.

For a deeper technical overview of aluminum extrusion, Wikipedia’s aluminum extrusion entry covers the process well.

2. Alloy Grades: 6063 vs 6061 vs 6060

Alloy composition directly affects extrudability, strength, corrosion resistance, and surface finish quality. Below is how the common grades compare for aluminum door and window profiles.

Alloy Grade	Composition	Tensile Strength	Key Properties	Best For
6063-T5	Al-Mg-Si (Mg 0.45–0.9%, Si 0.2–0.6%)	≥ 157 MPa	Excellent extrudability, good corrosion resistance, superior anodizing response, smooth surface	The industry default — over 90% of aluminum door and window profiles worldwide. Casement windows, sliding doors, residential and commercial fenestration.
6063-T6	Same composition, higher temper	≥ 215 MPa	Higher strength than T5, slightly lower extrudability	Large-span windows, high wind-pressure zones, heavy-duty sliding doors
6061-T6	Al-Mg-Si-Cu (adds Cu)	≥ 260 MPa	Higher strength, good weldability, rougher surface finish, harder to extrude	Structural applications, curtain wall mullions, oversized commercial entrances
6060-T66	Al-Mg-Si (lower alloy content)	≥ 190 MPa	Excellent extrudability for complex thin-wall sections, European standard for precision profiles	High-end European window systems, slim-line profiles, thermally broken systems

Our practical recommendation: For 90% of window and door projects, use 6063-T5. In our experience, it balances strength, extrudability, cost, and surface finish better than anything else. Move to 6061-T6 only when you need structural-grade strength, and 6060-T66 only for European precision systems with thin-wall extrusions.

Factory reality: 6063-T5 accounts for more than 95% of our aluminum door and window profile orders. In contrast, the other alloys are not bad — they are simply unnecessary for most jobs.

You can compare the full alloy specifications on the Aluminum Association website.

3. Thermal Break vs Non-Thermal Break: Not Just Price

Aluminum conducts heat at roughly 200 W/m·K. By contrast, PA66 GF25 thermal break strip conducts at about 0.30 W/m·K — a difference of roughly 700 times.

Non-thermal-break profiles are a single piece of aluminum. As a result, heat travels straight through the frame from outside to inside. In winter, therefore, the interior frame surface is cold. Thermal break profiles split the aluminum into inner and outer sections, connecting them with a low-conductivity polyamide strip. Because of this, heat transfer drops dramatically.

Non-Thermal-Break Profiles

• Wall thickness: typically 1.2–1.4 mm
• Frame U-value (Uf): 5.0–7.0 W/m²K
• Suitable for: interior partitions, mild climates, budget-constrained projects, temporary structures
• Not suitable for: exterior windows in cold climates, energy-code-compliant buildings, condensation-sensitive environments

Thermal Break Profiles

• Wall thickness: 1.4–2.0 mm (GB/T 8478-2020 requires ≥1.8 mm for exterior window load-bearing sections)
• Frame U-value (Uf): 1.8–3.2 W/m²K depending on PA66 strip width
• Condensation: interior frame surface stays within 2–3°C of room temperature
• Sound reduction: PA66 dampens vibration, adding 2–5 dB compared with non-thermal-break profiles
• Suitable for: all exterior windows and doors with temperature variation, energy-code-compliant buildings

System Window Profiles

System profiles are engineered as a complete solution — extrusion, thermal break, hardware, seals, and glazing are designed and tested together. In other words, the supplier warrants whole-window performance, not just the profile.

• Wall thickness: 1.6–2.2 mm
• Frame U-value (Uf): 2.0–2.5 W/m²K (system-tested)
• Suitable for: high-end residential, villas, commercial buildings requiring certified whole-window performance

Metric	Non-Thermal Break	Thermal Break	System Window
Frame Uf value	5.0–7.0 W/m²K	1.8–3.2 W/m²K	2.0–2.5 W/m²K
Condensation risk	High	Low	Very low
Sound reduction (frame)	Minimal	+2–5 dB	+3–7 dB
Energy code compliance	Fails most modern codes	Meets ASHRAE, EN standards	Exceeds most codes
Relative cost	Lowest	Moderate	Highest

Read more about thermal bridging and why it matters in building envelopes on the U.S. Department of Energy building envelope guide.

4. Profile Series Explained (55, 60, 70, 80, 90)

The series number is the cross-section width of the profile in millimetres. For example, a 70-series profile has a 70 mm frame depth. This number tells you how much internal space is available for thermal breaks, chambers, glass units, and hardware.

Series	Frame Width	Recommended Wall Thickness	PA66 Strip Width	Typical Glass Config	Best Application
55	55 mm	1.4 mm	12–14 mm	5+12A+5 double	Low-rise, mild climate, budget projects
60	60 mm	1.4 mm	14–18 mm	5+12A+5 or 5+20A+5	Standard residential, mid-rise apartments
70	70 mm	1.4–1.8 mm	20–24 mm	5+22A+5 or triple glazing	Most homes — bedrooms, living rooms, mid-to-high rise
80	80 mm	1.6–2.0 mm	24–32 mm	Triple glazing or laminated insulating	High-rise (20+ floors), cold climates, large windows, roadside noise
90+	90 mm+	≥2.0 mm	28–34 mm	Triple + laminated composite	Ultra-high-rise, typhoon zones, Passive House, luxury villas

A common trap: series number alone does not guarantee performance. We have seen 80-series profiles with 1.4 mm walls and PVC insulation strips perform worse than a properly built 70-series with 1.8 mm walls and PA66 thermal breaks. Therefore, always verify the combination of series, wall thickness, strip material, and strip width together.

5. Wall Thickness — Where Suppliers Cut Corners

Wall thickness is the single most important structural specification for aluminum door and window profiles. Indeed, it directly affects wind pressure resistance, structural integrity, and safety — especially in high-rise buildings where window failure can be catastrophic.

China’s national standard GB/T 8478-2020 sets the following minimums:

Application	Minimum Wall Thickness	Recommended for High-Rise
Interior doors	≥ 1.4 mm	1.4 mm
Interior windows	≥ 1.4 mm	1.4 mm
Exterior windows (main load-bearing)	≥ 1.8 mm	1.8–2.0 mm
Exterior doors (main load-bearing)	≥ 2.0 mm	2.0–2.2 mm
Heavy-duty sliding doors	≥ 2.0 mm	2.0–3.0 mm

Additional thickness considerations:

• Single pane area > 3–4 m²: increase wall thickness or add intermediate mullions.
• Buildings above 20 floors: we recommend ≥2.0 mm regardless of profile series, due to higher wind loads.
• Coastal and typhoon-prone areas: profiles should be tested for the wind pressure class required by local codes.

Receiving inspection tip: measure wall thickness at the main load-bearing sections — the vertical stiles and horizontal rails of the sash — with a caliper. Do not measure the glazing bead or auxiliary sections. Some suppliers meet the spec only at non-critical points. Unfortunately, we have seen this more than once.

The GB/T 8478-2020 standard is published by the Standardization Administration of China (note: public link varies; verify with your local standards body).

6. Thermal Break Strips: PA66 vs PVC

The thermal break strip is the heart of a thermally broken profile. Use the right material and the window insulates for 25 years. Conversely, use the wrong one and the profile delaminates after a few thermal cycles.

Why PA66 GF25

PA66 GF25 is polyamide 66 with 25% glass fibre. The glass fibre is not just for strength — it brings the coefficient of thermal expansion close to aluminum’s.

• Aluminum CTE: about 23 × 10⁻⁶/K
• PA66 GF25 CTE: about 25 × 10⁻⁶/K

Because the two materials expand and contract at almost the same rate, the composite stays bonded through summer heat and winter cold. If the expansion rates do not match, the strip and aluminum separate — consequently, the thermal break becomes no break at all.

PA66 vs PVC: Simple Field Tests

• Burn test: hold a lighter to a small strip. PA66 self-extinguishes when the flame is removed and smells like burning hair. Meanwhile, PVC keeps burning, produces black smoke, and has a sharp acidic odour.
• Laser marking: genuine PA66 strips carry a laser code — brand, model, standard, production date. By contrast, PVC strips usually have no marking.
• Bend test: PA66 GF25 can be bent to 90 degrees without whitening or cracking and springs back. PVC whitens and snaps.

Our blunt advice: if a supplier cannot provide a material certificate for their thermal break strips, assume they are using PVC. The price gap is large, and so is the performance gap.

PA66 Strip Width	Frame Uf Value	Application
14.8–18.6 mm	2.6–3.2 W/m²K	Moderate climates, standard residential
20.0–24.0 mm	2.0–2.6 W/m²K	Cold climates, energy code compliance
28.0–34.0 mm	1.8–2.2 W/m²K	Passive House, net-zero buildings

Combined with double or triple Low-E argon-filled glazing, whole-window Uw values below 0.8 W/m²K are achievable — meeting Passive House requirements.

7. Surface Treatment Options

Surface treatment affects both aesthetics and durability. Specifically, the right choice depends on environment, design requirements, and budget.

Treatment	Thickness	Durability	Color Options	Best For
Anodizing	10–25 μm	20–30 years	Silver, bronze, black, champagne (metallic tones)	High-end commercial, coastal environments, natural metallic appearance
Powder Coating	60–80 μm	20–25 years	Full RAL range (200+ colors), custom matches	Most common choice — residential, commercial, best cost-to-performance ratio
Fluorocarbon (PVDF)	≥ 40 μm (2-coat) or ≥ 65 μm (4-coat)	25–30+ years	Metallic, custom, high-gloss	High-rise curtain walls, UV-intense climates, premium projects
Electrophoretic (ED)	12–25 μm	20+ years	Limited (clear, bronze, black)	High-end residential, smooth finish, stain-resistant
Wood Grain Transfer	60–80 μm base + sublimation	15–20 years	Realistic wood textures (oak, walnut, teak, etc.)	Villas, resorts, wood aesthetic without maintenance

Practical guidance:

• Standard urban environment: powder coating, RAL color of choice.
• Within 5 km of the sea: powder coating with QUALICOAT Seaside certification, or PVDF.
• High UV (tropical, high altitude): PVDF for maximum UV resistance.
• Wood look required: wood grain transfer on a powder-coated base.

QUALICOAT and QUALANOD specifications are maintained by QUALICOAT and QUALANOD.

8. Opening Types and Sealing Performance

The opening mechanism determines the sealing method, and the sealing method sets the ceiling for thermal and acoustic performance. Therefore, choosing the right opening type is just as important as choosing the right profile.

Opening Type	Sealing Method	Thermal Performance	Sound Insulation	Best For
Casement (side-hinged)	Compression gasket — multi-point lock compresses seal uniformly around perimeter	Excellent	Excellent (35+ dB)	Bedrooms, living rooms, high-performance windows
Tilt & Turn	Dual-function: tilt for ventilation, turn for full opening. Compression seal when closed.	Excellent	Excellent (35+ dB)	European-style homes, secure ventilation, high-rise apartments
Sliding	Brush seals — sliding panels cannot achieve compression	Moderate (always lower than hinged)	Moderate (25–30 dB)	Patios, balconies, space-constrained openings, budget projects
Top-Hung (Awning)	Single-sided compression seal	Good	Good (30–32 dB)	Bathrooms, basements, ventilation during rain
Folding (Bi-fold)	Compression at hinges, brush between panels	Good to moderate	Good (30–32 dB)	Large openings, indoor-outdoor living, commercial entrances
Fixed (Picture)	No opening — sealed frame	Best	Best (35+ dB)	View-only windows, curtain wall panels, large glass facades

The hierarchy is simple: compression-sealed openings (casement, tilt-turn) always outperform brush-sealed sliding openings. If energy efficiency and sound insulation matter, choose hinged. However, if space is the constraint, sliding is acceptable — but expect roughly 15–20% lower thermal performance.

9. 5-Step Profile Selection Framework

This is the decision path we use when a fabricator or contractor asks us for a recommendation. To make it repeatable, we break it into five steps.

Step 1: Determine the climate zone.

• Annual temperature variation < 15°C: non-thermal break may suffice for interior; thermal break for exterior.
• Variation 15–30°C: thermal break is mandatory for exterior windows. Use 60–70 series with 20 mm+ PA66 strips.
• Variation > 30°C: choose wide thermal breaks (24–34 mm). Use 70–80 series and consider triple glazing.
• Coastal/tropical: focus on corrosion resistance — QUALICOAT Seaside powder or PVDF. Specify 6063-T5 alloy with adequate wall thickness.

Step 2: Check building height and wind load.

• Below 6 floors: standard wind load class. Use 55–60 series.
• 6–20 floors: elevated wind load. Use 70 series minimum with 1.8 mm wall thickness.
• Above 20 floors: high wind load. Use 80+ series with 2.0 mm wall thickness and tested wind pressure class.
• Typhoon zones: consult local building code for design wind pressure. You may need 90+ series with reinforced sections.

Step 3: Match glass configuration to profile capacity.

• 55–60 series: handles double insulating glass up to 5+20A+5 (30 mm total).
• 70 series: handles double insulating up to 5+27A+5, or triple glazing 5+9A+5+9A+5.
• 80–90 series: handles triple glazing, laminated insulating, and heavy composite units.

Step 4: Select surface treatment based on environment.

• Standard urban environment: powder coating (60–80 μm, full RAL range).
• Coastal (within 5 km of sea): QUALICOAT Seaside powder, or PVDF.
• High UV (tropical, high altitude): PVDF.
• Aesthetic requirements (wood look): wood grain transfer.

Step 5: Verify hardware compatibility.

• European system windows: 15/20 mm Euro-groove hardware slot — accepts Roto, G-U, Siegenia, Maco.
• Chinese standard hardware: check groove dimensions match your hardware supplier.
• Multi-point locking: ensure profile chambers can accommodate espagnolette rods and shoot bolts.

10. Standards and Certifications

When evaluating suppliers of aluminum door and window profiles, these standards matter:

Material and Profile Standards

• GB/T 5237 — Chinese national standard for aluminum alloy extruded profiles (dimensional tolerances, mechanical properties, surface quality)
• GB/T 8478-2020 — Aluminum windows and doors standard (wall thickness, performance requirements)
• EN 755 / EN 12020 — European standards for extruded precision profiles
• EN 14024 — Thermal break profile mechanical integrity standard
• ASTM B221 — American standard for aluminum alloy extruded bars, rods, wire, profiles
• AAMA TIR-A8 — Structural performance of composite thermal barrier framing systems

Surface Treatment Certifications

• QUALICOAT — Quality label for powder coating on aluminum (Seaside class for coastal)
• QUALANOD — Quality label for anodized aluminum
• AAMA 2604 / 2605 — American architectural coating performance specifications

System and Performance Standards

• EN ISO 10077-1/2 — Thermal performance of windows, doors and shutters
• ASHRAE 90.1 — Energy standard for buildings (window U-factor requirements)
• NFRC 100 / 200 — North American window energy rating
• EN 14351-1 — Window and external pedestrian door product standard

Factory Certifications

• ISO 9001 — Quality management system
• ISO 14001 — Environmental management system
• CE marking — European conformity for products sold in the EU

11. Frequently Asked Questions

What is the minimum wall thickness for aluminum window profiles?

Per GB/T 8478-2020, exterior windows require ≥1.8 mm at main load-bearing sections. Interior windows require ≥1.4 mm. Exterior doors require ≥2.0 mm. Moreover, for buildings above 20 floors or high wind-pressure zones, 2.0 mm is recommended.

What is the difference between thermal break and non-thermal break profiles?

Thermal break profiles use a PA66 GF25 polyamide strip to separate interior and exterior aluminum sections, blocking heat transfer. As a result, frame U-value drops from 5.0–7.0 W/m²K (non-thermal break) to 1.8–3.2 W/m²K (thermal break). On the other hand, non-thermal-break profiles conduct heat directly, causing energy loss and condensation in cold weather.

What does the series number mean?

The series number indicates the profile’s cross-section width in millimetres. For example, a 70-series profile has a 70 mm frame depth. Larger numbers mean more internal space for thermal breaks, chambers, and glass units. However, series number alone does not guarantee quality — wall thickness and strip material are equally important.

Which aluminum alloy is best for window and door profiles?

6063-T5 is the industry standard for over 90% of aluminum door and window profiles worldwide. In fact, it offers the best balance of strength (≥157 MPa tensile), corrosion resistance, extrudability, and surface finish. Use 6061-T6 for structural applications and 6060-T66 for European precision systems requiring thin-wall extrusions.

How long do aluminum window profiles last?

With proper surface treatment (powder coating or anodizing at specified thickness), aluminum window profiles last 30–50 years with minimal maintenance. In addition, the surface coating typically carries a 20–25 year warranty. Furthermore, aluminum itself does not rust or degrade — the limiting factors are usually hardware, seals, and insulating glass units, which may need replacement after 15–20 years.

Can aluminum profiles be used in coastal areas?

Yes, but the surface treatment must be specified for salt spray resistance. For example, powder coating with QUALICOAT Seaside certification or PVDF fluorocarbon coating provides the necessary protection. Anodizing with ≥15 μm oxide film thickness is also suitable. Nevertheless, standard powder coating without Seaside certification may show pitting within 5–7 years in direct coastal exposure.

How do I verify profile quality from a supplier?

Request these documents: (1) material test report showing alloy grade and temper, (2) dimensional inspection report with wall thickness measurements, (3) surface treatment thickness certificate, (4) thermal break strip material certification (PA66 GF25, not PVC), and (5) relevant standards compliance (GB/T 5237, EN 14024, etc.). Additionally, physically measure wall thickness at main load-bearing sections and inspect surface finish for uniformity.

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About Naview Aluminium

Naview Aluminium (Foshan Naview New Building Materials Co., Ltd.) has been manufacturing aluminum door and window profiles since 2005. Our 600,000 m² facility produces 300,000 tons of aluminum profiles annually, serving window fabricators, curtain wall contractors, and building material distributors in over 80 countries.

Our door and window profile capabilities include:

• 6063-T5/T6 and 6060-T66 alloy extrusion (22 extrusion lines, 1800–4000 ton press capacity)
• Thermal break profile assembly with PA66 GF25 strips (14.8–34 mm widths, EN 14024 certified)
• In-house powder coating (QUALICOAT certified), anodizing, PVDF, and wood grain transfer
• Custom profile design and die manufacturing for OEM/ODM projects
• Deep processing: CNC cutting, drilling, milling, and assembly-ready kits

Certifications: ISO 9001, ISO 14001, QUALICOAT, QUALANOD, CE, GB/T 5237 compliant.

Contact our technical team for profile specifications, custom extrusion quotes, or project consultations.

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This article was written by the Naview Aluminium technical team with 20+ years of manufacturing experience. Technical data references GB/T 8478-2020, GB/T 5237, EN 14024, EN ISO 10077, and AAMA standards. Last updated: July 2026.