Boeing BMS Specification 7050 Aluminum Alloy Aluminum

BMS 7-323

7050 Aluminum Alloy – High Strength, Fatigue Tolerant, Stress Corrosion Resistant

Boeing Material Specification – 7050 Aluminum Alloy Plate
High Strength Fatigue Tolerant | Stress Corrosion Resistant | Plate

AS9100D / ISO 9001

Mill Test Reports

2–4 Week Delivery

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Quick Specification Facts

Spec Number BMS 7-323

Material 7050 Aluminum Alloy

Spec Type BMS (Boeing Material Specification)

Category 7050 Aluminum Alloy

Composition Al-Zn-Mg-Cu (Zn 5.7–6.7%, Mg 1.9–2.6%, Cu 2.0–2.6%)

Condition T7451, T7452, T7351 (Overaged / Stress Relieved)

Product Forms Plate

Certification AS9100D / ISO 9001 with full MTR traceability

Specification Overview

BMS 7-323 is a Boeing Material Specification (BMS) covering high strength, fatigue tolerant, stress corrosion resistant 7050 aluminum alloy plate. Issued by Boeing Commercial Airplanes, this specification defines the stringent material, mechanical, and quality requirements for 7050 aluminum plate used in critical aerospace structural applications. BMS 7-323 material is widely specified for primary aircraft structures where an optimum combination of high strength, fracture toughness, fatigue resistance, and resistance to stress corrosion cracking is required.

7050 aluminum alloy (UNS A97050) belongs to the 7xxx series of high-strength aluminum alloys and is alloyed principally with zinc, magnesium, and copper. The alloy's chemistry and controlled temper conditions (typically T7451, T7452, or T7351) provide an outstanding balance of mechanical properties. The overaged temper conditions deliver superior resistance to stress corrosion cracking compared to peak-aged (T651) tempers, making BMS 7-323 plate the material of choice for thick-section aerospace structural components such as wing spars, bulkheads, and fuselage frames.

Available Product Forms

Plate

BMS 7-323 material is supplied in Plate form in the overaged / stress-relieved temper condition per Boeing specification requirements. Custom sizes, thicknesses, and cut-to-size pieces are available upon request. Contact our materials specialists for non-standard dimensions or special processing requirements.

Nominal Chemical Composition

Element	Symbol	Range / Limit	Notes
Zinc	Zn	5.7–6.7%	Primary strengthening element
Magnesium	Mg	1.9–2.6%	Secondary strengthening (MgZn₂ precipitates)
Copper	Cu	2.0–2.6%	Enhances strength and SCC resistance
Zirconium	Zr	0.08–0.15%	Grain structure control; replaces chromium
Iron	Fe	0.15% max	Controlled impurity
Silicon	Si	0.12% max	Controlled impurity
Aluminum	Al	Balance	Base metal

Chemical composition ranges are nominal per AMS 2014 / Aluminum Association 7050 limits. Consult the current issue of BMS 7-323 for precise Boeing-specific requirements. Aero-Vac provides full mill test reports (MTRs) with certified chemistry for every order.

Key Properties & Specification Details

Property / Attribute	Details
Specification Number	BMS 7-323
Issuing Organization	Boeing Commercial Airplanes (Boeing Material Specification)
Material Type	High Strength, Fatigue Tolerant, Stress Corrosion Resistant Aluminum Alloy Plate
Alloy	7050 (UNS A97050)
Typical Tempers	T7451, T7452, T7351 (Overaged / Stress Relieved)
Available Forms	Plate
Typical UTS (T7451)	~495–510 MPa (72–74 ksi)
Typical Yield Strength (T7451)	~427–455 MPa (62–66 ksi)
Density	2.83 g/cm³ (0.102 lb/in³)
Stress Corrosion Resistance	Excellent – overaged temper provides superior SCC resistance vs. T651
Fatigue Tolerance	High – optimized for damage-tolerant structure designs
Weldability	Limited – not typically arc welded in structural applications
Certification Available	AS9100D / ISO 9001, Certificate of Conformance, MTR

Typical Applications

Commercial & Military Aircraft Structures: Primary structural components including wing spars, wing ribs, fuselage frames, and bulkheads where high strength combined with damage tolerance and SCC resistance is critical.

Wing Skin & Spar Applications: Thick plate sections for upper and lower wing skins, spar webs, and spar caps on commercial and business jet aircraft requiring optimum fatigue and fracture toughness.

Defense & Military Aerospace: Airframe components for fighter aircraft, military transport aircraft, and rotorcraft where the combination of light weight, high strength, and corrosion resistance is essential.

Machined Structural Components: Heavy machined parts such as ribs, fittings, brackets, and frames that are machined from thick plate stock and require excellent machinability combined with high structural performance.

Aerospace Tooling & Fixtures: High-strength tooling plates, jigs, and fixtures used in aerospace manufacturing where dimensional stability and strength-to-weight ratio are important.

Frequently Asked Questions – BMS 7-323

What is BMS 7-323 and what does it cover?

BMS 7-323 is a Boeing Material Specification covering high strength, fatigue tolerant, stress corrosion resistant 7050 aluminum alloy plate. Issued by Boeing Commercial Airplanes, this specification defines the chemistry, mechanical properties, and quality requirements for 7050 aluminum plate used in critical aerospace structural applications. The alloy's nominal chemistry of Zn 5.7–6.7%, Mg 1.9–2.6%, and Cu 2.0–2.6% combined with controlled overaged temper conditions (typically T7451 or T7452) delivers an outstanding combination of high strength, excellent fracture toughness, fatigue resistance, and superior stress corrosion cracking resistance. It is widely used in Boeing commercial aircraft primary structures including wing spars, bulkheads, and fuselage frames.

What is the difference between 7050 and 7075 aluminum alloy?

Both 7050 and 7075 are high-strength 7xxx-series aluminum alloys, but they differ in several important ways. 7050 (as covered by BMS 7-323) contains zirconium instead of chromium as a grain refiner, which provides better quench sensitivity and allows it to retain its mechanical properties in thick sections—making it superior for thick plate applications. 7050 also provides better stress corrosion cracking resistance in the overaged temper (T7451) compared to 7075-T651. 7075-T651 offers slightly higher peak strength but is more susceptible to SCC. For thick structural plate applications typical of Boeing primary structures, 7050 per BMS 7-323 is generally preferred due to its better through-thickness properties and damage tolerance characteristics.

Does Aero-Vac supply BMS 7-323 with full mill test reports and certifications?

Yes. All BMS 7-323 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 Boeing program requires Boeing-approved source documentation or additional special process certifications, our quality team can coordinate as needed.

What tempers and plate thicknesses of BMS 7-323 does Aero-Vac stock?

Aero-Vac maintains inventory of BMS 7-323 / 7050 aluminum plate in the most common tempers including T7451 (stress relieved by stretching), T7452 (stress relieved by compression), and T7351. We stock a range of plate thicknesses from thin gauge through heavy plate sections. Standard mill sizes as well as custom-cut pieces, discs, and blocks can be processed at our in-house facility at the Port of Kalama. For specific temper requirements, non-standard thicknesses, or large-quantity orders, our team can source from our global supplier network. Contact us with your specific size and temper requirements for a prompt quote.

What are the typical lead times for BMS 7-323 material?

In-stock BMS 7-323 / 7050 aluminum plate 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 or non-standard thicknesses requiring mill production may require 4–8 weeks depending on quantity and temper. We prioritize urgent aerospace and defense requirements and will always provide honest, upfront delivery estimates. Rush processing is available on select items. Contact us to discuss your specific delivery requirements.

Can Aero-Vac provide value-added processing for BMS 7-323 aluminum plate?

Yes. Aero-Vac operates a complete in-house processing facility at our Port of Kalama location. For BMS 7-323 / 7050 aluminum plate, we offer precision saw cutting (including disc and plate cutting), surface grinding, trepanning, milling, and turning. 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. Our experienced team understands the machining characteristics of 7050 aluminum and can assist with optimizing your processing approach. Contact us to discuss your specific processing requirements.

Need BMS 7-323 material or a custom quote?

Our aluminum specialists can provide fast pricing, availability, and technical guidance for your BMS 7-323 / 7050 aluminum requirements.