Aluminum Extrusion: Techniques, Alloys, and Applications

1. Introduction

Aluminum extrusion is a critical metal-forming process that enables the production of complex cross-sectional profiles with high dimensional accuracy and excellent surface finish.

Its widespread application ranges from architectural curtain walls and window frames to automotive structural components, aerospace frames, electronics heat sinks, and consumer goods.

This article provides an in-depth, multi-perspective exploration of aluminum extrusion, covering the fundamental principles,

materials selection, detailed process steps, tooling design, mechanical and surface properties, major applications, advantages and limitations, standards, and quality control.

2. What is Aluminum Extrusion？

At its core, extrusion is a plastic deformation process.

An aluminum billet (a pre-heated, cylindrical piece of aluminum alloy) is placed into a chamber, and a hydraulic ram applies force to push the billet through a shaped die opening.

As the metal is squeezed under high pressure, it flows plastically around the edges of the die, emerging on the far side as a continuous profile whose cross-section matches the die’s aperture.

Key to this process is the fact that aluminum’s yield strength decreases with increasing temperature,

enabling it to deform more readily at elevated temperatures (typically 400–500 °C for common aluminum extrusion alloys).

Once the extrudate exits the die, it retains the precise geometry of the die shape, with only a slight reduction in cross-section due to die clearance and billet shrinkage upon cooling.

3. Materials and Alloys

Commonly Used Aluminum Alloys for Extrusion

Although pure aluminum (1100) can be extruded, most structural and high-performance applications require alloyed grades.

The 6xxx series (Al-Mg-Si) represents roughly 70–75 % of all extruded profiles worldwide, owing to its excellent balance of strength, corrosion resistance, and extrudability.

Other significant series include:

Key Material Properties Affecting Extrudability

• Flow Stress and Temperature Sensitivity: The force required to extrude a billet depends on its yield stress at the extrusion temperature.
  Alloys with lower flow stress at hot temperatures are easier to extrude, but may sacrifice peak strength.
• Work Hardening and Age-Hardening Response: Alloys that respond well to precipitation (age) hardening (e.g., 6061, 6063)
  can be extrusion-quenched and then artificially aged (to T5 or T6 temper) to achieve elevated strengths.
• Crack Susceptibility: High-strength alloys (7000 series, 2000 series) are more prone to hot cracking unless the process is tightly controlled (die design, billet homogenization, extrusion speed).
• Grain Structure Control: Homogenization (holding the billet at an intermediate temperature prior to aluminum extrusion) helps eliminate dendritic segregation, reduce cracking, and achieve uniform mechanical properties.

4. The Extrusion Process of Aluminum Alloys

Billet Preparation and Preheating

Billet Material and Casting

• Aluminum billets used for extrusion typically come from direct-chill (DC) casting or continuous casting.
  Common alloys include 6xxx-series (e.g., 6063, 6061, 6105) and certain 7xxx- or 2xxx-series grades when higher strength is needed.
• Prior to aluminum extrusion, cast billets often undergo a homogenization heat treatment (e.g., 500–550 °C for 6–12 hours) to reduce chemical segregation and dissolve low-melting eutectic phases.
  Homogenization yields a more uniform microstructure, minimizes hot-shortness (cracking during hot deformation), and improves overall extrudability.

Surface Inspection and Machining

• Once homogenized, billets are scanned for surface defects (cracks, oxide folds, or inclusions).
  Any visible anomalies may be machined off or the billet set aside.
  A smooth, oxide-free surface helps prevent die galling or localized frictional heating that could initiate cracks.

Preheating to Extrusion Temperature

• Billets are placed into a billet preheat furnace, where they are uniformly heated to
  the alloy’s target extrusion temperature (typically 400–520 °C for most 6xxx-series, slightly lower for 7xxx-series to avoid excessive grain growth).
• Precise temperature control (±5 °C) is crucial. If a billet is too cold, the flow stress is higher, increasing the required extrusion force and risking cracks.
  If too hot, grain growth or incipient melting of low-temperature eutectics can weaken the billet.
• Billet preheat times depend on diameter and wall thickness.
  A 140 mm (5.5″) diameter billet typically requires 45–60 minutes in a well-calibrated furnace to reach uniform temperature from core to surface.

Extrusion Press Setup and Billet Loading

Extrusion Press Types

• Hydraulic Direct-Feed Press: The most common. A hydraulic ram pushes the billet through a stationary die assembly.
  Rated in “tonnage” (for example, a 3,000-ton press can generate ~3,000 metric-tonnes of force).
• Indirect (Backward) Extrusion Press: The die is mounted on the moving ram, which presses into a stationary billet container.
  Friction between the billet and container is nearly eliminated, lowering required pressure. Such presses are often smaller (200–1,200 ton) but can achieve higher extrusion ratios.
• Hydrostatic Extrusion Press: The billet is encased in a sealed chamber filled with pressure fluid (usually oil).
  As the press applies force, fluid pressure uniformly surrounds the billet, causing it to flow through the die.
  These specialized presses minimize friction and allow extrusion of brittle or high-strength alloys, albeit at higher capital cost.

Billet Loading and Centering

• A preheated billet is lifted (often via an overhead crane or automated billeting system) and placed into the container.
• Centering/Alignment: Most modern facilities use an alignment fixture or locating ring at the container mouth; the billet must sit flush with the die face to avoid eccentricity.
  Misaligned billets can fatally damage dies or introduce non-uniform flow patterns (leading to surface cracks or dimensional inaccuracies).

Use of a Dummy Block / Bridge Die

• In direct extrusion, there is a short “dummy block” (a sacrificial insert) placed between the ram face and billet.
  The dummy block protects the die from sudden hammering if the billet has a slightly smaller diameter or if minor misalignment occurs.
• The ram first contacts the dummy block, which then transmits the force onto the billet more uniformly.
  In indirect extrusion, the ram itself carries the die, so no separate dummy block is used.

Metal Flow and Die Interaction

Ram Advancement and Pressure Buildup

• Once the billet is in position, the operator (or a CNC control system) initiates the extrusion stroke.
  Hydraulic oil pumps build pressure until the ram moves forward, compressing the billet.
• As the ram pushes, internal billet pressure rises. In direct extrusion, friction between billet and container walls dissipates some energy; in indirect or hydrostatic, frictional losses are far lower.

Die Entry Geometry

• Entry Angle: A typical die has a tapered entry zone (often 20–30°) that guides the metal from the larger billet cross-section into the smaller profile shape.
  If this angle is too shallow, metal can fold or “inversion” of flow lines can occur; if too steep, metal may separate from the die surface, causing turbulence and surface waviness.
• Porting / Preform Zone: When a profile has multiple cavities or intricate hollows,
  the die designer will create a “porting section” to divide the billet metal into separate streams, which then recombine into the final shape.
  Proper porting prevents metal shuffling issues (internal cracks, lamination).

Bearing (Land) Section

• After the porting zone, the “bearing length” (also called land) is a straight, constant cross-section section of the die that finalizes dimensions and controls surface finish.
• Length of the bearing is typically 4–8 mm for thin-wall 6xxx-series extrusions;
  longer bearings increase dimensional accuracy but require higher extrusion force and raise frictional heat. Short bearings reduce force but sacrifice tolerance.

Die Lubrication and Coating

• A thin film of graphite-based or ceramic-enhanced lubricant is applied to the billet’s entry face and sometimes the container walls.
  This lubricant reduces friction, extends die life, and helps evacuate trapped air.
• Effective lubrication is especially critical for high-ratio extrusions (> 50:1) or for hard-to-extrude alloys (such as 7000-series).
• Some die faces are coated with wear-resistant layers (e.g., tungsten carbide spray, nickel aluminide) to minimize die-metal galling and erosion.

Friction and Heat Generation

• As metal flows through the die, friction between the aluminum and die surfaces generates heat, momentarily raising the metal’s temperature by 20–50 °C above billet temperature.
  Excessive temperature rise can cause grain coarsening, surface tearing, or die galling.
• Indirect and hydrostatic extrusion significantly reduce friction heat at the billet/container interface, enabling larger extrusion ratios with less thermal input.

Variations in Extrusion Methods

Direct (Conventional) Extrusion

• Setup: Die is fixed to a bolted shoe at the front of the container. The ram (via a dummy block) pushes the billet forward so that the metal flows through the stationary die.
• Advantages: Simpler die alignment and loading; straightforward tooling; common across most large extrusion presses.
• Limitations: Friction between billet and container walls can be significant (20–70 % of total extrusion pressure),
  requiring a more powerful press for a given extrusion ratio. Higher friction also increases die wear.

Indirect (Backward) Extrusion

• Setup: The die is mounted on the face of the ram. When the ram advances into the container, the billet remains static, and metal flows backward through the die into the extrusion fields.
• Advantages: Virtually no container/billet friction, which lowers required ram pressure (sometimes by 20–40 %).
  Because friction is low, extruding brittle or thin-wall alloys is more feasible.
• Limitations: Die must be mounted on the ram, so the ram bore must be hollow or specially configured; overall tooling complexity increases.
  Setup times may be longer, and die changes on some presses are more time-consuming.

Hydrostatic Extrusion

• Setup: The billet is surrounded by a fluid (e.g., oil) in a closed chamber.
  As the press compresses the fluid, pressure is uniformly applied around the billet’s circumference, forcing it through a die at the chamber’s exit.
• Advantages: Friction at both die face and container walls is almost zero—this permits extremely high extrusion ratios (often > 100:1)
  and the forming of high-strength or otherwise difficult alloys (e.g., certain 7xxx or 5xxx grades) without cracking.
  Surface finish is typically superior, with very low incidence of surface tear.
• Limitations: Equipment cost is very high. Chambers must reliably seal under high pressure; any fluid leak can cause safety hazards.
  Throughput is lower for large sections, so hydrostatic extrusion is usually reserved for smaller-cross-section rods, wires, or specialty profiles.

Cooling and Quenching

Purpose of Quenching

• Most heat-treatable aluminum alloys (e.g., 6xxx-series, 7xxx-series) rely on rapid cooling (quenching) immediately after extrusion to “lock in” a supersaturated solid solution.
  Later, artificial or natural aging will precipitate strengthening phases.
• Quenching also prevents excessive grain growth in alloys that would coarsen at elevated temperatures.

Methods of Cooling

• Water Quench Bath: The most common approach. As the hot extrudate exits the die, it passes directly into a water bath (depth ~150–200 mm).
  Flow rates and bath temperature (often 60–80 °C) are controlled so that the profile cools uniformly.
• Spray Quench: High-pressure nozzles spray water (sometimes with air) onto the profile. Ideal for complex cross sections where certain hollow sections might trap water if simply immersed.
• Air Cooling / Forced Air: Used only for alloys where rapid quenching is not critical (e.g., 6063 if a T4 temper is acceptable).
  May also be used as a “pre-cool” zone before water quench to reduce thermal shock.
• Combination Quench: Some plants use an initial forced-air stage (to cool from 500 °C down to ~250 °C), followed by a water spray or immersion.
  This staggered approach minimizes warping in very long or thick profiles.

Avoiding Thermal Shock

• Immersing a 500 °C aluminum profile abruptly into 20 °C water can induce tensile stresses on the cooler outside and compressive stresses inside.
  If cooling is too aggressive, the profile can crack or warp.
• Proper nozzle placement, flow rate adjustment, and water temperature control ensure uniform cooling rates and minimize local stress concentrations.

Post-Extrusion Stretching and Straightening

Residual Stress and Profile Deformation

• As the extruded profile cools, uneven contraction (especially in long or asymmetrical cross sections) can cause bowing or twisting.
  These distortions must be corrected to meet straightness tolerances (ASTM B221, EN 755).

Stretching Machines

• A typical stretching operation:

• • One end of the profile is clamped, and the other is attached to a hydraulic (or mechanical) puller.
  • The profile is elongated (4–5 % of its length) by applying a controlled tensile force.
  • A straight-edge fixture holds the profile in position, keeping it straight while under tension.
  • Once held under tension, the profile is released and allowed to “spring back” slightly; because the material yielded during stretching, it retains a straighter shape than before.

• Cycle Timing: Stretching typically occurs within minutes of quench, before significant grain stabilization.
  Profiles shorter than 6 m may be stretched in one piece; longer profiles (up to 12 m or more) are spliced or handled sequentially in segments.

Straightening Only

• For some thick, high-rigidity profiles, a lighter straightening fixture (e.g., mechanical press or leveling machine) can be used without significant tensile elongation.
  However, for thin-walled or highly asymmetrical shapes, full stretching is preferred to avoid springback issues.

Aging and Tempering

Heat-Treatable vs. Non-Heat-Treatable Alloys

• Heat-Treatable Alloys (e.g., 6000-series, 7000-series, some 2000-series) gain strength through precipitation hardening.
  Rapid quench after extrusion produces a supersaturated solid solution;
  subsequent aging (either at room temperature or an elevated temperature) precipitates strengthening phases (Mg₂Si in 6xxx, η′/η in 7xxx).
• Non-Heat-Treatable Alloys (e.g., 1xxx and most 5xxx alloys) rely on work hardening (H-tempers).
  After extrusion, they typically undergo controlled cooling, but no subsequent artificial aging is needed for maximum strength.

Common Tempers

• T4 Temper (natural aging): The extruded profile is quenched and then stored at ambient temperature for days or weeks.
  Suitable where moderate strength (~70–80 % of T6) is acceptable.
• T5 Temper (artificial aging without solution-treat): The extruded profile is immediately cooled (quench) and then placed into an aging oven (e.g., 160–175 °C for ~6–10 hours).
  Yields higher strength than T4 but below T6.
• T6 Temper (solutionizing + artificial aging): The profile is solution-heat-treated (e.g., ~530 °C for 1–2 hours), quenched, and then artificially aged (e.g., 160–180 °C for 8–12 hours).
  Produces the highest strength for 6xxx-series (e.g., 6061-T6) or 7xxx-series (e.g., 7075-T6) extrusions.

Practical Considerations

• Many extrusion houses offer T5 as a standard in-line service because it avoids a separate solutionizing furnace.
  For very large or complex profiles, post-extrusion solutionizing (to achieve T6) may be performed in a dedicated batch oven after all lengths have been cut to finished size.
• Over-aging (holding at elevated temperature too long or at too high a temperature) can reduce elongation or cause unwanted coarsening of precipitates, lowering toughness.

Direct vs. Indirect vs. Hydrostatic: Comparative Notes

5. Secondary Operations and Surface Finishing

Once the raw extruded profiles are cut to length and stretched, many applications require secondary machining or aesthetic finishing.

Cutting to Length

• Flying Cut-Off Saws: In-line sawing stations that match extrusion speed—ensures continuous operation without stopping the extrusion press.
• Offline Cut-Off Saws: Manual or automatic bandsaws or circular saws used after the extrusion run to cut profiles to customer-specified lengths.

Machining and Drilling Operations

• CNC Milling, Drilling, and Tapping: To create holes, slots, or complex features.
  Aluminum’s machinability allows high feed rates and long tool life if proper tool geometry and cutting fluids are used.
• Milling T-Slots or Custom Re-Entrant Features: Sometimes required when die-cost or geometry constraints prohibit direct extrusion of certain features.

Surface Treatments

Anodizing

• Creates a controlled, porous oxide layer (typical thickness 5–25 µm).
• Improves corrosion resistance, surface hardness, and aesthetic appearance.
• Allows for subsequent dyeing (coloring) or sealing (enhanced wear resistance).

Powder Coating

• Thermoset polymer powders are electrostatically applied and cured (180–200 °C).
• Provides a uniform, durable finish with superior scratch and chemical resistance.
• Available in virtually unlimited colors and textures.

Liquid Painting (Wet Coat)

• Conventional spray or electrostatic paint lines.
• More vulnerable to chipping than powder coating but often chosen for complex color blends or extremely smooth finishes.

Mechanical Finishes

• Brushing: Produces a consistent linear grain—popular for architectural handrails and appliance trim.
• Polishing/Buffing: Achieves a mirror-like finish—commonly used for decorative applications.
• Sandblasting or Bead Blasting: Imparts a uniform matte or satin texture—frequently applied before painting to improve adhesion.

Specialized Coverings

• PVDF (Polyvinylidene Fluoride) Coatings: Often used for exterior architectural elements (<0.3 mm thickness).
  PVDF provides exceptional UV resistance, color retention, and weatherability.
• Powder-Coated Wrinkle or Wrinkled Finishes: Impart a textured appearance for industrial or decorative uses.

6. Key Industrial Applications of Aluminum Extrusion

Construction and Architectural Systems

• Window and Door Frames: Extruded 6063‐T5/T6 profiles with integrated thermal breaks, drainage channels, and weather seals.
• Curtain Wall and Facade Components: Complex mullions and transoms designed for precision fit, high wind load, and thermal performance.
• Structural Framing: Modular railing systems, canopy support struts, curtainwall sub‐frames.
• Solar Mounting Structures: Lightweight racking rails and mounting brackets.

Automotive and Transportation

• Chassis and Frame Members: Extruded crash beams, bumper reinforcements, suspension components—all utilizing high‐strength 6005A or 6061 alloys to meet crashworthiness and weight targets.
• Roof Rails, Door Sills, and Body Moldings: Extrusions that deliver both aesthetic and structural function.
• Heat Exchangers and Radiators: Engine oil coolers, AC evaporators, and condenser headers made by extruding specialized 6000‐series or 1xxx series alloys.

Aerospace

• Wing Ribs, Fuselage Stringers, and Longerons: 6000‐ and 7000‐series alloys extruded to exacting dimensional tolerances, then age-hardened to T6 or T651.
• Interior Cabin Components: Overhead bins, seat tracks, window frames—often coated or anodized for aesthetics and wear resistance.
• Landing Gear Components: Some subcomponents like torque tubes or drive‐shaft housings use extruded profiles for lightweight strength.

Electronics and Heat-Exchange

• Heat Sinks for Power Electronics: Extruded 6063 or 6061 profiles offering intricate fin geometries and large surface areas.
• LED Lighting Fixtures: Extrusions providing both structural mounting and thermal management, often with integrated channels for LED strips and wiring.
• Transformer and Bus Bar Enclosures: Pure aluminum extrusions or laminated “aluminum core/copper-clad” profiles for power distribution.

Consumer Products and Furniture

• Sporting Goods: Bicycle frames (6016, 6061 alloys), ladder rails, tent poles.
• Display Units and Shelving: Modular extruded frames for retail fixtures, trade show booths, and exhibition stands.
• Furniture Components: Table legs, chair frames, drawer slides—often anodized for interior aesthetics.

Industrial Machinery and Automation

• Machine Frames and Guarding: 30×30 mm to 80×80 mm modular profiles (based on 6063 or 6105) with T-slots for easy mounting of panels, sensors, conveyors.
• Conveyor Rails and Linear Motion Guides: Extruded guides with integrated raceways for ball bearings, enabling compact, precise linear systems.
• Safety Fencing and Protective Barriers: Lightweight, reconfigurable panels that meet industrial safety standards (ISO 14120, OSHA).

7. Advantages and Limitations of Aluminum Extrusion

Advantages

Design Flexibility and Complex Cross-Sections

• Extrusion enables intricate hollow sections, multi-chambered profiles,
  and integrated channels (e.g., wiring ducts, gasket grooves) that would be difficult or expensive via other methods.
• Low-cost modification of die design allows relatively quick iteration of profile geometry.

High Material Utilization

• Compared to milling from plate or forging and machining, extrusion generates minimal swarf/waste.
  Unused scrap can be re-melted and returned to the billet production loop with minimal loss.

Excellent Recyclability and Sustainability

• Aluminum is infinitely recyclable with only ~5 % of the energy required to produce primary aluminum from bauxite.
• Many aluminum extrusion companies operate with closed-loop scrap recycling, reducing carbon footprint and raw material costs.

Relatively Low Tooling Cost Compared to Die Casting for Medium Runs

• While extrusion dies have a significant upfront cost (US $2,500–$15,000+ depending on complexity),
  for moderate production volumes (thousands to tens of thousands of parts), aluminum extrusion can be more economical than die casting.

Superior Finishing Options

• Extruded surfaces can be anodized to provide durable, corrosion-resistant, and aesthetically pleasing finishes.
• Tight tolerances (±0.15 mm) reduce the need for secondary machining or grinding.

Limitations

Initial Die Cost for Very Complex Shapes

• Extremely intricate profiles may require multi-piece split dies or specialized coatings (e.g., ceramic, WC coatings), driving die costs upward of US $50,000.
• For ultra-low volumes (< 100 m of profile), a custom die setup may not be justified.

Geometric Constraints

• Minimum Wall Thickness: Typically 1.5 mm for standard alloys. Thinner features increase the risk of surface cracking, die tearing, or post-extrusion warping.
• Sharply Reduced Cross Sections: Sudden changes in cross-section can cause metal packing (over-extrusion) or under-extrusion; smooth transitions and generous fillets are required.

Surface Defects

• Visible “die lines” or “stringers” can appear if die maintenance lapses, or if alloy cleanliness is poor.
• Non-metallic inclusions or oxide films (from poor lubrication control) may lead to surface blemishes that are difficult to mask, even after anodizing.

Alloy-Specific Drawbacks

• Some high-strength alloys (7000, 2000 series) are more prone to hot cracking and require extremely tight process controls, which raises both scrap and tooling costs.
• Lower-cost 6xxx series may not meet high-temperature or extremely high-fatigue demands in some critical aerospace or defense applications.

8. Quality Control and Industry Standards

Relevant Standards

• ASTM B221 (“Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes”):
  Defines chemical composition, mechanical property requirements, and dimensional tolerances for various alloy/temper designations and tempers.
• EN 755/EN 12020: European standards for extruded aluminum profiles—specify tolerances for linear and angular dimensions, surface quality, and mechanical properties.
• JIS H4100: Japanese standard covering similar extruded product specifications.

Dimensional Inspection

• Calipers and Micrometers: Manual inspection for features accessible with hand tools.
• Coordinate Measuring Machines (CMM): High-accuracy 3D scanning of intricate profiles, especially when verifying complex tolerances and quality for aerospace or automotive applications.
• Optical Scanners: Non-contact laser scanners can quickly compare entire cross-section against CAD model to detect warping or die wear.

Mechanical Testing

• Tensile Testing: Coupons cut from extruded pieces to measure yield strength, ultimate tensile strength, and elongation in both longitudinal and transverse directions (anisotropy can exist).
• Hardness Testing: Rockwell or Vickers tests to confirm temper condition, especially for artificial aging (T6) versus natural aging (T4).
• Fatigue Testing: Occasionally required for critical structural components (e.g., aerospace frames) to validate long-term performance under cyclic loads.

Surface Quality Assessment

• Visual Inspection: Checking for surface blemishes such as extrusion lines, scratches, oxide films, or blemishes.
• Coating Adhesion Testing: For anodized or painted surfaces, standardized tests (e.g., ASTM D3359 tape test) ensure proper bonding.
• Corrosion Testing: Salt spray (ASTM B117) or humidity chamber tests to simulate outdoor exposure for architectural or marine applications.

Certification and Traceability

• Material Traceability: Each extrusion run is typically accompanied by a mill test certificate, listing chemical composition, temper, mechanical properties, and test results.
• ISO 9001 / IATF 16949: Many extrusion facilities serving automotive or aerospace
  OEMs operate under ISO 9001 (Quality Management) or IATF 16949 (automotive quality) systems to ensure process consistency and traceability.

9. Conclusion

Aluminum extrusion stands as a cornerstone technology in modern manufacturing, enabling the efficient production of complex, high-strength, lightweight profiles across countless industries.

By forcing heated billets through tailored dies, extruders can achieve remarkable geometric versatility with minimal material waste.

When coupled with secondary machining and high-quality surface treatments (anodizing, powder coating), extruded profiles deliver outstanding mechanical performance, corrosion resistance, and aesthetic appeal.

Key takeaways include:

• Alloy Selection: The 6000-series remains dominant for its balanced strength, extrudability, and anodizing potential,
  while 7000-series and 2000-series alloys address specialized high-strength and fatigue demands.
• Process Control: Meticulous billet homogenization, temperature management, die design,
  and lubrication practices are essential to produce defect-free extrusions, especially for complex or high extrusion ratios.
• Design Practice: Adhering to geometric guidelines (minimum wall thickness, fillets, uniform section) ensures dimensional accuracy and avoids warping.
• Sustainability: Aluminum extrusion’s recyclability and lightweighting potential make it a linchpin of carbon reduction strategies in transportation, construction, and consumer electronics.
• Future Trends: Emerging process innovations (hydrostatic, ultrasonic), advanced alloys (nano-precipitates, functionally graded materials),
  and digital integration (Industry 4.0, IoT-enabled “smart” profiles) promise to extend extrusion’s capabilities well beyond today’s achievements.

As industries increasingly demand lightweight, high-performance, and sustainable solutions, aluminum extrusion will continue to evolve,

driven by ongoing innovations in materials science, process technology, and digital manufacturing.

Keeping abreast of these developments is critical for engineers and designers seeking to harness aluminum extrusion’s full potential in next-generation products and infrastructure.

Choose LangHe Aluminum Extrusion Services

LangHe leverages its state-of-the-art extrusion equipment, extensive alloy portfolio, and proven process expertise to deliver turnkey aluminum extrusion solutions across a wide range of applications.

from lightweight structural components and industrial automation to high-performance heat sinks and architectural finishes.

With rigorous quality control and flexible delivery options, we help our customers rapidly realize enhanced product value.

For more technical details or to request samples, please feel free to contact the LangHe technical team.

 

FAQs

What tolerances and dimensions can be achieved in aluminum extrusion?

• Outside Dimensions: Typically ±0.15 mm to ±0.50 mm, depending on wall thickness and alloy.
• Inside (Hollow) Dimensions: Generally ±0.25 mm to ±1.0 mm.
• Straightness: After stretching, profiles often meet < 0.5 mm deflection per meter.
• Thicker walls and simpler cross-sections achieve tighter tolerances more easily; thin walls (< 1.5 mm) or highly complex profiles may have wider tolerances and require more precise process control.

What are common surface treatments for extruded aluminum profiles?

• Anodizing: Creates a durable oxide layer (5–25 µm) that improves corrosion resistance, hardness, and allows for color dyeing. Ideal for decorative architectural or consumer goods.
• Powder Coating: Electrostatic application of polymer powder, then curing. Provides uniform, durable finish with excellent scratch and chemical resistance.
• Liquid Paint (Wet Painting): Spray or electrostatic methods for specialized color or texture requirements.
• Mechanical Finishes: Brushing (linear grain), polishing (mirror finish), sandblasting/bead blasting (matte/satin texture).
• PVDF Coatings (e.g., Kynar®): High-performance coatings for exterior architectural elements with exceptional UV, chemical, and weather resistance.