AMS Specification 7050 Aluminum Alloy Aluminum

AMS 4201

7050 Aluminum Alloy – Plate

Aluminum Alloy, Plate 6.2Zn – 2.3Cu – 2.2Mg – 0.12Zr (7050-T7651) Solution Heat Treated, Stress Relieved, and Overaged

AS9100D / ISO 9001

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Quick Specification Facts

Spec Number AMS 4201 (AMS4201)

Material 7050 Aluminum Alloy

Spec Type AMS (Aerospace Material Specification)

Category 7050 Aluminum Alloy

Composition 6.2Zn – 2.3Cu – 2.2Mg – 0.12Zr

Temper / Condition T7651 – Solution Heat Treated, Stress Relieved, and Overaged

Product Forms Plate

Certification AS9100D / ISO 9001 with full MTR traceability

Specification Overview

AMS 4201 (also referenced as AMS4201) covers 7050 aluminum alloy in the form of plate in the T7651 temper condition. This specification is issued by SAE International and is widely used in aerospace, defense, and high-performance structural applications requiring an exceptional combination of high strength, toughness, and resistance to stress corrosion cracking. The nominal composition of 6.2% Zinc, 2.3% Copper, 2.2% Magnesium, and 0.12% Zirconium provides excellent mechanical properties in thick section plate forms.

The T7651 temper designation indicates that the material has been solution heat treated, stress relieved by stretching, and then overaged (precipitation heat treated) to provide improved resistance to stress corrosion cracking and exfoliation corrosion compared to T651 temper, while retaining a high proportion of the peak-aged strength. The controlled Zirconium addition inhibits recrystallization and grain growth, contributing to excellent fatigue performance and fracture toughness. AMS 4201 plate is commonly used in structural airframe components, wing spars, bulkheads, and other thick-section aerospace structural applications.

Available Product Forms

Plate

AMS 4201 material is supplied as Plate per specification requirements. Plate is available in a range of thicknesses, widths, and lengths to suit aerospace and industrial structural applications. Custom-cut plate and precision-sawn blanks are available upon request. Contact our materials specialists for non-standard dimensions or special requirements.

Nominal Chemical Composition

Element	Symbol	Nominal %	Notes
Zinc	Zn	5.7 – 6.7% (~6.2%)	Primary strengthening element – forms MgZn₂ precipitates
Copper	Cu	2.0 – 2.6% (~2.3%)	Enhances strength and stress corrosion resistance
Magnesium	Mg	1.9 – 2.6% (~2.2%)	Solid solution strengthener; contributes to precipitation hardening
Zirconium	Zr	0.08 – 0.15% (~0.12%)	Inhibits recrystallization; improves fatigue and fracture toughness
Manganese	Mn	0.10% max	Kept low to prevent interaction with Zr
Silicon	Si	0.12% max	Impurity; controlled to low levels
Iron	Fe	0.15% max	Impurity; controlled to low levels
Aluminum	Al	Balance	Base metal

Chemical composition ranges are nominal. Consult the current issue of AMS 4201 for precise minimum/maximum requirements. Aero-Vac provides full mill test reports (MTRs) with certified chemistry for every order.

Key Properties & Specification Details

Property / Attribute	Details
Specification Number	AMS 4201 (AMS4201)
Issuing Organization	SAE International (Society of Automotive Engineers)
Material Type	Aluminum Alloy – Plate
Alloy Designation	7050 (UNS A97050)
Temper	T7651 – Solution Heat Treated, Stress Relieved, and Overaged
Nominal Composition	6.2Zn – 2.3Cu – 2.2Mg – 0.12Zr
Available Forms	Plate
Strength	Very High – one of the highest strength aluminum alloys; typical UTS ~76–83 ksi depending on thickness
Fracture Toughness	Excellent – superior to 7075-T651 at equivalent strength levels
Stress Corrosion Resistance	Very Good – T7651 overaged temper provides greatly improved SCC resistance vs. T651
Machinability	Good – machines well with carbide tooling; recommended for high-speed CNC operations
Weldability	Limited – not generally recommended for fusion welding; mechanical joining preferred
Magnetic Properties	Non-magnetic
Certification Available	AS9100D / ISO 9001, Certificate of Conformance, MTR

Typical Applications

Aerospace Structural Components: Fuselage frames, bulkheads, wing spars, wing skins, upper wing covers, and other primary airframe structures requiring the highest strength-to-weight ratio with excellent fracture toughness and SCC resistance.

Defense & Military: Armor plate, military aircraft structural members, armored vehicle components, and missile airframes where high strength and low weight are critical performance requirements.

Tooling & Mold Making: Large-scale injection mold tooling, jigs, fixtures, and precision machined tooling blocks that benefit from excellent dimensional stability and machinability of 7050-T7651 plate.

Space & Launch Vehicles: Structural panels, adapter rings, and primary structural components for launch vehicle and spacecraft applications requiring optimized strength, weight, and environmental resistance.

High-Performance Industrial: Precision machined components, high-load structural members, and performance-critical applications in semiconductor equipment, medical devices, and other industries requiring premium aluminum plate.

Frequently Asked Questions – AMS 4201

What is AMS 4201 and what does it cover?

AMS 4201 (also written AMS4201) is an SAE International aerospace material specification covering 7050 aluminum alloy in the form of plate in the T7651 temper. The nominal chemistry of 6.2% Zinc, 2.3% Copper, 2.2% Magnesium, and 0.12% Zirconium delivers an outstanding combination of high strength, excellent fracture toughness, and superior resistance to stress corrosion cracking. It is widely used in aerospace, defense, tooling, and high-performance structural applications where a premium high-strength aluminum plate is required.

What does the T7651 temper designation mean for AMS 4201?

The T7651 temper designation indicates a specific sequence of thermal and mechanical processing: the material is first solution heat treated (T), then stress relieved by controlled stretching (51), and finally overaged by a two-stage precipitation heat treatment (T7). The overaging step takes the alloy past its peak strength condition to provide significantly improved resistance to stress corrosion cracking and exfoliation corrosion compared to the T651 (peak-aged) temper, while retaining a high level of tensile strength. The stress relief by stretching also improves dimensional stability during subsequent machining operations, making T7651 an excellent choice for thick plate aerospace components.

Does Aero-Vac supply AMS 4201 with full mill test reports and certifications?

Yes. All AMS 4201 material supplied by Aero-Vac is fully traceable to mill test reports (MTRs) confirming chemical composition and mechanical properties per the specification. We are AS9100D/ISO 9001 certified with a 99.6% quality rating. Every order ships with certificates of conformance, material certifications, and chemical/mechanical test reports. Electronic delivery of all documentation is available for fast turnaround. If your program requires additional special process certifications, our quality team can coordinate as needed.

What sizes of AMS 4201 plate does Aero-Vac stock?

Aero-Vac maintains inventory of AMS 4201 7050-T7651 aluminum plate in a range of thicknesses, widths, and lengths. We carry standard mill sizes and can provide precision-cut plate blanks from our in-house processing facility at the Port of Kalama. For non-standard dimensions, our team can source from our global supplier network. Contact us with your specific size requirements and we will provide a prompt quote with availability and lead time.

What are the typical lead times for AMS 4201 material?

In-stock AMS 4201 material is typically available for same-day or next-day shipment. For custom-cut or specially processed orders, our standard lead time is 2–4 weeks—significantly faster than the industry average of 8–12 weeks. Specialty items requiring mill production may require 4–8 weeks depending on quantity and dimensions. We prioritize urgent aerospace and defense requirements and will always provide honest, upfront delivery estimates. Rush processing is available on select items.

Can Aero-Vac provide value-added processing for AMS 4201 material?

Yes. Aero-Vac operates a complete in-house processing facility at our Port of Kalama location. For AMS 4201 aluminum plate, we offer precision saw cutting, surface grinding, milling, and turning services. We also provide comprehensive mechanical and non-destructive testing services in-house. Having all capabilities under one roof allows for faster turnaround, tighter quality control, and reduced overall cost compared to using multiple vendors. Contact us to discuss your specific processing requirements for 7050-T7651 aluminum plate.

Need AMS 4201 material or a custom quote?

Our aluminum specialists can provide fast pricing, availability, and technical guidance for your AMS 4201 requirements.