Most aluminium buying errors are not metallurgical. They are administrative: a plate order certified against an extrusion standard, an MTC that does not match what the drawing requires, a temper that was never stated on the purchase order. Each one is cheap to prevent and expensive to discover at inspection. This guide covers how high-strength aluminium is actually specified, sourced, certified and shipped, so the paperwork and the metal agree with each other.

At Plus Metals we supply aerospace aluminium alloys as bar, rod, plate and sheet, quoted against the grade, temper, product form and standard written on the enquiry.

Start With the Product Form, Not the Grade

Aluminium is bought and certified by product form, and each form has its own specification with its own mechanical minimums. The most common order error is naming a grade and leaving the form open, or pairing a plate with an extrusion standard. The grade may be correct while the material delivered still fails inspection, because the applicable standard was never the right one.

Product form Governing ASTM Typical AMS route What the buyer must specify
Sheet and plate ASTM B209 AMS 4027, AMS 4028 Temper, thickness, width/length, flatness class, clad or unclad
Extruded bar, rod, profiles ASTM B221 AMS 4152, AMS 4166, AMS 4172 Temper, cross-section, extrusion tolerance class, whether extruded or drawn
Drawn rod and bar ASTM B211 AMS 4112, AMS 4122 Temper, diameter/section, drawn tolerance class, surface finish
Clad sheet and plate ASTM B547 As per core spec plus cladding Core alloy and temper, cladding alloy, number of sides, cladding thickness
Forging stock ASTM B247 AMS 4123, AMS 4124, AMS 4167 Temper, class (forging vs extrudable), grain direction if specified
Wire and cable ASTM B316 / B839 AMS 8120, AMS 8130 series Temper or temper class, diameter, surface condition

Note the pattern: B209 is sheet and plate, B221 is extruded, B211 is drawn. All three cover high-strength aerospace grades, and quoting the wrong one is a routine rejection cause. AMS specifications run in parallel for aerospace work and must be stated separately — material certified only to ASTM B209 is not automatically acceptable to an aerospace buyer or its first-tier suppliers.

Temper Is Not Optional

An aluminium grade without a temper is an incomplete specification. The same 7075 alloy differs by more than a factor of two in strength between O and T6, and the over-aged T7 tempers trade strength for corrosion resistance. Writing "7075" on a purchase order and receiving T6 material is not a substitution error — the order was never specific enough to be wrong.

  • O — annealed. Soft, ductile and corrosion resistant.
  • T4 — solution treated and naturally aged. The usual condition for material that will be formed.
  • T6 — solution treated and artificially aged. Peak strength.
  • T51 — the stress-relieving treatment applied to plate and bar after ageing.
  • T73 / T7351 — over-aged. The SCC-resistant temper; roughly 12% below T6 in strength.
  • T76 / T7651 — over-aged. The exfoliation-resistant temper.

The double-asterisk convention matters at inspection. T651** means the value in the standard is not met and the actual agreed value applies; that agreed value has to be stated on the purchase order, not resolved later in correspondence. For a T651 plate order, always state the thickness, because the minimum tensile strength falls from 538 MPa at 6.35 mm to 462 MPa at 101.6 mm.

Material Test Certificates: 3.1 vs 3.2

The certificate type is a contractual decision, not a formality, and it should be written on the order rather than requested afterwards.

Certificate Who verifies Typical use Cost implication
EN 10204 2.2 Manufacturer Non-critical components, general industrial Lowest
EN 10204 3.1 Independent inspector, accredited The usual requirement for aerospace aluminium. Confirms the product complies with the order, verified by an independent inspector
EN 10204 3.2 Buyer's inspector or nominated party Contract, pressure-equipment and nuclear work Highest

Both 3.1 and 3.2 confirm the product complies with the order, and both are issued by the manufacturer. The difference is who does the verifying: 3.1 is verified by an accredited independent inspector appointed by the manufacturer, while 3.2 is additionally verified by the buyer or the buyer's nominated party, who is entitled to witness sampling and testing. That is why the point that catches buyers out is scope — if the order itself was wrong, a valid 3.1 certificate does not rescue it, and no certificate type does. On aerospace and defence work, 3.1 is the standard expectation; pressure and nuclear applications usually require 3.2 or inspection by a third party such as SGS, BV, Lloyd's or TÜV.

Whatever the type, the certificate should report chemistry, tensile and yield strength, elongation, and the product dimensions — and it should carry heat or lot identification that ties it to the physical material.

Common Specification Mistakes to Avoid

  • Clad orders without cladding detail. "2024-T3 Alclad" is incomplete. Specify the cladding alloy (commonly 1100 or 7076) and the number of clad sides. For two-sided 7075, nominal cladding is about 4% of gauge below 0.062 in (1.57 mm) and 2.5% above it.
  • Ordering to a temper the form cannot supply. Some combinations are simply not produced in certain forms; confirm the form and temper exist as a pair before promising a delivery date.
  • Confusing AMS with ASTM. They are not interchangeable. AMS carries tighter chemistry tolerances and mandatory mechanical properties; many aerospace primes specify AMS even where an ASTM number exists.
  • Ignoring EN equivalents on export. European buyers frequently require the EN designation (EN 573-3, EN 755-2 and similar) alongside or instead of ASTM, and the certificate must cite the standard the inspection will be judged against.
  • Expecting fracture toughness values. 7075 sheet and plate is not supplied with guaranteed minimum fracture toughness. If damage tolerance governs the design, that has to be established by the design authority.
  • Welding grade for welded structures. The 7000 series is rated poorly weldable. If the design requires welded 7xxx structure, the weld procedure and heat-affected zone properties must be qualified rather than assumed.

Forms We Supply

We supply high-strength aerospace aluminium in the forms that carry a defined specification, quoted against grade, temper and standard:

  • Plate and sheet — 2000 and 7000 series in O, T6, T651, T73, T7351, T76 and T7651 conditions, unclad or Alclad to ASTM B209 / B547.
  • Bar and rod — round, square and rectangular sections in drawn or extruded condition to ASTM B211 / B221, covering the 2011, 2014, 2017, 2024, 7050, 7068, 7075, 7175, 7449 and 7475 grades.
  • Forging stock — to ASTM B247 and the relevant AMS bar specifications.
  • Custom-cut sizes — sheared or sawn to your dimensions or drawing, to reduce wastage and downstream processing time.

We do not list tubes or pipe among standard high-strength offers. If your requirement is tubular, raise it as an enquiry and we will confirm what is available for the specific grade and standard rather than quoting a nominal form we cannot certify.

Every supply is issued with an EN 10204 3.1 MTC as standard, reporting chemical analysis and mechanical results against the standard named on your order. See our aluminium sheet, plate and extrusion supply page for the wider range, or the 7075 alloy grade detail.

High-strength aluminium alloy inspection and packing for export

Inspection and Testing

Inspection is where the specification either proves itself or does not. The four checks below are routine on every shipment; the additional tests depend on what the drawing demands.

Inspection and testing of high-strength aluminium alloy

  • Chemical composition — spectrometry against the standard's specified element ranges. On 7075 this matters disproportionately: the chromium window is only 0.18–0.28%, and it is the element that governs stress-corrosion cracking resistance.
  • Mechanical properties — tensile strength, yield strength and elongation, tested on the specified specimen and reported against the correct product form. For 7075 plate, the applicable minimum depends on thickness.
  • Dimensional verification — thickness, width, length, flatness and straightness against the ASTM or AMS tolerance class stated on the order. Aluminium's modulus is roughly a third of steel's, so unsupported plate distorts more readily in handling and needs proper stacking support.
  • Surface condition — rolling marks, scratches, die marks, and for clad material, bond integrity and cladding continuity.

Additional testing is quoted on request rather than assumed: ultrasonic and dye-penetrant flaw detection, conductivity testing for heat-treat verification, hardness testing, tensile testing at elevated temperature, stress-corrosion cracking testing on the T7 tempers, and metallographic grain-structure examination.

One point worth confirming early: 7075 sheet and plate carries no guaranteed minimum fracture toughness. If your design authority requires a fracture toughness value, that has to be arranged as a specific test requirement at enquiry stage, not expected on the MTC.

Where These Alloys Actually Go

  • Aerospace and defence — wing skins, spars, ribs, stringers, fuselage panels, missile and launch vehicle structures, landing gear and fasteners. This is the dominant market for 2000 and 7000 series grades.
  • Automotive, EV and motorsport — chassis, suspension, wheel and battery enclosure components where mass reduction directly affects range and handling.
  • Elevated-temperature structural duty — 2618 and 7050 where an aluminium structure must retain strength at moderate heat.
  • Precision engineering — machined bar components, tooling and fixtures.

One correction worth making explicitly, because it is the most common mis-specification we see: marine hulls and offshore structures are not an application for 2000 or 7000 series aluminium in bare form. These alloys have poor corrosion resistance in the peak-strength condition and are vulnerable to stress-corrosion cracking and exfoliation under sustained load in seawater. Marine construction uses 5000 series alloys, or clad material, or a T73-type temper. Where a marine enquiry arrives for "high-strength structural aluminium", the temper and cladding are the questions to settle before anything else.

Packing, Labelling and Export Logistics

Aluminium is light for its strength, but it is unforgiving in transit. A bundle that is under-supported internally will bow, and a bowed plate fails a flatness check on arrival even though nothing was damaged in any meaningful sense. Our packing practice reflects that.

Element How we handle it
Form Plate and sheet strapped in bundles or on pallets; bar and rod bundled by section size and length, with larger diameters sleeved individually.
Internal support Straps placed at points that prevent edge damage, with dunnage or separators so sheets cannot rub or bow against each other.
Surface protection Interleaved or lined to prevent scratching and, for clad or precision-machined surfaces, protected against handling marks.
Edge marking Grade, temper, standard, lot/heat number, dimensions, piece count and weight, marked so the material can be identified at unpacking without breaking the bundle.
Clad material Clad side identified explicitly on the bundle so the correct face is not machined away.
Documentation MTC, packing list and commercial invoice in the format your customs and receiving inspection require, sequenced to arrive with the consignment.

Shipment is quoted on the Incoterm that suits your operation. EXW suits buyers arranging their own collection and freight. FOB suits buyers taking over the main carriage cost from the port of loading. CIF is FOB plus the ocean freight and marine insurance the seller arranges. DDP suits buyers who need the shipment delivered duty and tax cleared to their door. In every case be explicit about the port and Incoterms® 2020 version named on the quotation, and about where terminal handling ends and the buyer's carrier begins.

We supply to Europe, the Middle East, Asia, Africa and the Americas, and we will state lead time, packing method and Incoterm in the quotation so nothing about the delivery is open to interpretation later.

How to Get an Accurate Quotation

Send us these six items and we can quote without a clarification cycle:

  1. Alloy and temper — e.g. 7075-T651, not "7075".
  2. Product form — plate, sheet, extruded bar, or drawn bar. This determines the applicable standard.
  3. Dimensions — thickness and width/length for plate; diameter or section and length for bar.
  4. Quantity in pieces and total weight, with acceptable tolerance on both.
  5. Governing specification — ASTM B209 / B221 / B211 / B247, an AMS number, or the EN equivalent your inspection will be judged against.
  6. Delivery terms — Incoterm and destination port.

Add the service environment if corrosion behaviour is critical, and the clad details (alloy, side count) for any clad order. That is enough for us to confirm feasibility, certification scope and lead time in one response.

Request a Quotation

Whether it is a single test piece, a first prototype batch or a full production order, the same specification discipline applies. Tell us the grade, temper, form, dimensions, standard and delivery terms, and we will confirm what is available and what the certification will cover.

Request a Quote – Send alloy, temper, form and dimensions for pricing and lead time
Browse the range – www.plusmetals.in

Frequently Asked Questions

Q1. What certificate do you supply with high-strength aluminium?

An EN 10204 3.1 MTC as standard, reporting chemical analysis and mechanical results against the standard named on your order, with heat/lot identification. 3.2 certification with independent witnessing is available where the contract requires it — pressure equipment, nuclear work and some prime contractor packages. State the certificate type on the enquiry so it is quoted correctly.

Q2. Do I need to specify the temper, or will you choose the best one?

Specify it. The temper changes the strength by more than a factor of two between O and T6, and it decides the corrosion behaviour: T6 gives peak strength but is SCC-susceptible, while T73/T7351 gives about 12% less strength for markedly better SCC resistance. If you are unsure which fits your service condition, tell us the environment and load and we will recommend, then quote what you approve.

Q3. Can you supply aluminium against an AMS specification?

Yes. AMS is the standard aerospace route and runs alongside ASTM with tighter chemistry tolerances and mandatory mechanical properties. Quote the AMS number directly — material certified only to ASTM B209 is not automatically acceptable to an aerospace buyer, so if your drawing cites AMS it must be named on the order and on the certificate.

Q4. Do you supply clad (Alclad) plate?

Yes, to ASTM B547. A clad order needs the core alloy and temper, the cladding alloy, and the number of clad sides specified — "2024-T3 Alclad" on its own is incomplete and we will ask for those details before quoting. For two-sided 7075, nominal cladding thickness is about 4% of gauge below 0.062 in (1.57 mm) and 2.5% above it. The clad side is marked on the bundle so it is not machined away in error.

Q5. Which Incoterms can you quote, and can you cut to size?

We quote EXW, FOB, CIF and DDP depending on your destination and how much of the logistics you want to handle — tell us the term and port and we will price it into the quotation. Custom-cut sizes are available, sheared or sawn to your dimensions, which reduces wastage and downstream processing time; state the tolerance you can accept on cut dimensions.