4027 Aluminum (AMS 4027) Comprehensive Guide: Definition, Properties, Composition, and Applications

Thanks to 4027 aluminum’s balanced strength, good corrosion resistance, and excellent machinability, this alloy become a prefered material for many people using among aerospace, automotive lightweighting, and high-precision industrial component design.

 

This is not noly because the inherent properties of 4027 aluminum alloy itself, but also for it is certified to AMS 4027 standard, which means 4027 aluminum produced under strict standards and certified. This ensures consistency and stability of the material , giving designers and engineers confidence in critical applications.

 

 

 

 

What is 4027 Aluminum？

 

4027 Aluminum refers to 6061 aluminum alloy plate and sheet produced under strict specifications, specifically in compliance with AMS 4027. In simple terms, 4027 aluminum is 6061 aluminum plate and sheet that meets the AMS 4027 standard.

 

So, who created AMS 4027?

 

AMS 4027 is an aerospace material specification issued by SAE (the Society of Automotive Engineers, USA). It is a standard specifically written for 6061 aluminum alloy plate and sheet, and it clearly defines the following requirements:

• Chemical composition: Tight control of alloying elements such as magnesium, silicon, copper, and chromium.
• Mechanical properties: Requirements for tensile strength, yield strength, and elongation to ensure the material can handle loads in aerospace structures.
• Heat treatment conditions: States like T6 and T651 are specified to balance strength, toughness, and machinability.
• Dimensions and tolerances: Limits on thickness, width, and length, as well as flatness and surface quality standards.
• Inspection and testing methods: Including chemical analysis, mechanical testing, and microstructural inspection to ensure every batch meets the standard.

Because of these strict controls, 4027 aluminum offers excellent consistency and full traceability. That’s why aluminum plate and sheet certified to AMS 4027 are widely used in industries such as aerospace, automotive, and structural engineering, where strength, corrosion resistance, and machining performance are critical.

 

 

 

 

 

Chemical Composition of AMS 4027

 

 

AMS 4027 belongs to the 6061 aluminum alloy family. Its main chemical elements and their typical weight percentages are outlined below:

 

 

Table 1: Chemical Composition of AMS 4027

 

 

The composition design of AMS 4027 aluminum ensures a well-balanced combination of corrosion resistance, weldability, heat-treatment response, and mechanical performance. The strengthening phases formed by magnesium and silicon allow the alloy to achieve moderate strength in the T6 and T651 tempers, while still maintaining good ductility and fatigue life.

 

 

 

 

 

Mechanical and Physical Properties of AMS 4027

 

 

The physical and mechanical properties of AMS 4027 in the T6/T651 state are as follows:

 

 

Table 2: Mechanical and Physical Properties of AMS 4027

 

 

 

AMS 4027 (6061-T6/T651) combines properties that give it an excellent strength-to-weight ratio for weight-sensitive structural components. The key characteristics of 4027 Aluminum include:

 

 

High strength to support loads

 

With an ultimate tensile strength of 290–310 MPa and a yield strength of 241–276 MPa, the material can withstand significant tensile and compressive forces under static loading, meeting the structural demands of critical components.

 

 

Ductility and toughness for structural reliability

 

An elongation of 8%–12% and a modulus of elasticity of 68.9–70 GPa allow the material to store elastic energy and deform moderately under stress, reducing the risk of brittle failure.

 

 

Lightweight design and dimensional stability

 

• Low density (2.70 g/cm³) helps reduce overall weight, enabling lightweight structural design.
• A moderate coefficient of thermal expansion (23.6 µm/m·K) ensures minimal dimensional change with temperature fluctuations, maintaining structural precision and stability.
• Relatively high thermal conductivity (167 W/m·K) promotes efficient heat dissipation, reducing local thermal stress.

 

 

Fatigue performance for long-term load-bearing applications

 

Under typical conditions, the reference fatigue strength is ~95 MPa at 5×10⁸ cycles, making it suitable for components subjected to cyclic loading in aerospace and automotive structures, ensuring long-term reliability.

 

 

 

 

 

T6 and T651 Tempers of AMS 4027

 

AMS 4027 aluminum is commonly available in two tempers: T6 and T651. These tempers refer to different heat treatment and stress-relief processes, which influence strength, corrosion resistance, and dimensional stability of aluminum 4027. In general,

 

• T6 is high-strength aluminum suitable for general structural use.
• T651 is “stress-relieved T6”, ideal for large or precision components that must retain their shape during and after manufacturing.

 

Below is the table distinguish AMS 4027 aluminum Under T6 and T651 Temper:

 

 

Table 2: Comparison of AMS 4027-T6 Aluminum and AMS 4027-T651 Aluminum

 

 

 

 

 

 

Corrosion Resistance of 4027 aluminum

 

 

AMS 4027 aluminum is highly resistant to both air and saltwater corrosion. This is mainly thanks to the naturally forming aluminum oxide layer, which acts like a protective skin for the metal. On top of that, the way the magnesium-silicon phases are distributed in the material helps reduce tiny spots of corrosion, making the alloy even more reliable over time.

 

Compared with other common 6xxx series aluminum alloys, like 6063 or 6082, AMS 4027 stays more stable in humid, hot, and salty environments. That’s why it’s a popular choice for parts that are exposed to the elements for a long time—such as aircraft fuselage panels, car frames, housings, and even bridge structures—where durability really matters.

 

 

 

 

Weldability of 4027 Aluminum

 

AMS 4027 aluminum is easy to weld, including when it is in the strong T6 or T651 temper ( despite the material being heat-treated and strong). It can produce strong welds that resist cracking, making it reliable for structural parts. Common welding methods include TIG, MIG, and FSW. Its balanced magnesium and silicon content helps prevent brittle areas from forming in the weld zone, which reduces the risk of cracks.

 

 

 

 

The metal also has a stable internal structure thanks to the controlled distribution of strengthening phases, and in the case of T651, an additional stress-relief treatment reduces internal stresses that could cause warping or cracking during welding. By carefully controlling the heat applied during welding, the metal keeps most of its original strength and toughness near the welded area. This combination of properties makes AMS 4027 ideal for aircraft, car parts, and other structures where both strength and long-term reliability are essential.

 

 

 

 

Machinability of AMS 4027 Aluminum

 

 

 

AMS 4027 aluminum has excellent machinability, making it easy to cut, drill, and mill. Its key machining characteristics include:

 

• Moderate cutting forces, allowing the use of standard tools.
• Suitable for precision CNC machining and fabrication of complex geometries.
• Good formability, making it ideal for bending and stamping operations.
• Optimized machining processes help reduce internal stresses, improve dimensional accuracy, and maintain structural strength.

 

But why AMS 4027 aluminum has excellent machinability? This is because that:

 

• the T6 heat treatment usually brings a balance of hardness and toughness;
• the ratio of magnesium and silicon forms the Mg2Si (magnesium silicide) strengthening phase, which is uniformly distributed microscopically and provides a slight natural lubrication effect on the cutting tool during machining;
• if it is in the T651 condition, stress relief brings dimensional stability to the material.

 

 

 

 

Common Applications of 4027 Aluminum

 

 

AMS 4027, with its medium strength, good corrosion resistance, and machinability, is widely used across multiple industries. Common examples include:

 

 

1. Aerospace Applications

 

• Fuselage Panels: UAV body panels, spacecraft outer shells

 

• Wings: Tailplane skins, flap and aileron support structures
• Frames: Cockpit support frames, landing gear subframes, door frames
• Internal Structural Components: Cabin support beams, cargo compartment dividers
• Instrument Panels: Navigation dashboards, flight instrument supports

 

 

2.Automotive Industry

 

 

 

• Engine Components: Cylinder head brackets, piston pin supports
• Lightweight Body Structures: Hood support beams, trunk reinforcements
• Chassis Parts: Cross members, suspension brackets
• Exhaust System Parts: Intercooler mounts, tailpipe brackets
• Interior Components: Dashboard supports, seat frames, door handle mounts

 

 

3. Marine Applications

 

• Ship Hulls: Small speedboat hulls, commercial ship outer panels
• Deck Structures: Hatch frames, railing fixtures
• Interior Equipment: Cabin hinges,helm instrument panels
• Propulsion System Supports: Propeller brackets, engine mounts
• Other Parts: Fasteners, hatch bolts

 

 

4. Construction Applications

 

• Bridges: Main beams, connector plates
• Furniture: Cabinet structures, metal decorative pieces
• Architectural Decorative Elements: Handrails, railings, window frames
• Doors, Windows, and Facades: Door frame supports, curtain wall connectors, exterior cladding elements

 

 

5. Consumer Applications

 

• Electronic Enclosures: Laptop casings, phone frames, speaker housings

 

 

• Bicycle Frames: Road bike frames, mountain bike frames, folding bike frames

 

 

• Sports Equipment: Scooter frames, climbing gear brackets, fitness equipment supports
• Household Hardware: Lamp brackets, tool handles, kitchen fixture supports

 

 

 

 

Price Factors of 4027 Aluminum

 

 

The price of 4027 aluminum is mainly affected by the following factors:

 

 

1. Raw Material Market Price

 

Fluctuations in global aluminum prices directly impact the cost of 4027 aluminum. When aluminum ingot prices rise due to supply shortages or increased demand, the price of 4027 aluminum increases accordingly.

 

 

2. Sheet Size and Thickness

 

Larger sheet sizes and thicker plates generally result in higher prices due to increased material consumption, more demanding rolling processes, and higher production costs.

 

 

3. Heat Treatment Condition (T6 / T651)

 

Heat-treated tempers such as T6 or T651 typically cost more than untreated or basic tempers because they require additional solution heat treatment, aging processes, and stricter process control.

 

 

4. AMS Certification Availability

 

Materials supplied with AMS certification are priced higher due to rigorous testing, documentation, quality control, and full traceability required to meet aerospace standards.

 

 

5. Aerospace Grade vs. Industrial Grade

 

Aerospace-grade 4027 aluminum is generally more expensive than industrial-grade material because it offers tighter chemical composition limits, superior mechanical consistency, and stricter inspection standards.

 

 

6. Comparison with 6061 Aluminum

 

AMS 4027 is usually priced slightly higher than standard 6061 aluminum because it provides enhanced strength, stricter material consistency, and full traceability required for aerospace and high-performance applications.

 

 

 

 

Summary

 

AMS 4027 (4027 aluminum) is a high-performance, heat-treatable aluminum alloy sheet and plate material, offering medium to high strength, good machinability, and reliable structural stability. When properly processed and surface-protected, it meets the requirements of demanding engineering applications.

 

This alloy is widely used in aerospace, automotive, engineering structures, and industrial design applications. By selecting the appropriate heat treatment condition (T6 / T651), machining process, and a reliable material supplier, the full performance advantages of AMS 4027 aluminum can be effectively realized.

 

If your project involves high-reliability structural components or precision-machined parts, AMS 4027 aluminum is a material well worth considering.

 

 

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FAQs on AMS 4027 Aluminum

 

 

Q1: What is the difference between AMS 4027 and ASTM B209?

 

A: AMS 4027 is an aerospace specification that emphasizes material consistency, mechanical performance, and full traceability. ASTM B209 is an industrial standard with more flexible requirements, mainly used for general aluminum plate and sheet applications.

 

 

 

Q2: How is AMS 4027 different from standard 6061 aluminum?

 

A: AMS 4027 is the aerospace-grade specification of 6061 aluminum, subjected to stricter heat treatment, testing, and quality control. It offers higher performance consistency and is better suited for structural and precision-machined components.

 

 

 

Q3: What are the equivalent standards to AMS 4027?

 

A: Common equivalent standards include EN AW-6061, ISO 6061, and GB/T 3190. However, for aerospace or traceability-critical applications, AMS 4027 is preferred.

 

 

 

Q4: What temperature range can AMS 4027 withstand?

 

A: AMS 4027 performs reliably at room temperature and moderate service temperatures. When exposed to temperatures above 150°C (302°F) for extended periods, its strength may decrease and should be evaluated based on specific engineering requirements.

 

 

 

Q5: What inventory forms are commonly available for AMS 4027?

 

A: AMS 4027 is typically supplied in plate and sheet forms, with common tempers such as T6 and T651. Availability is more limited compared to standard 6061 aluminum, and custom cutting or fixed-length sizes may be offered by specialized suppliers.

 

 

 

Q6: Does AMS 4027 require surface treatment?

 

A: Due to its limited corrosion resistance, AMS 4027 is often treated with anodizing, Alclad (cladding), or protective coatings to enhance corrosion protection, especially for use in humid or corrosive environments.