Buying Certified Aerospace Material and Surplus Drops

What certified aerospace material means

It means the material conforms to a named specification and you can prove it with documents tied to the physical piece. Grade alone is not enough. A bar stamped "6Al-4V" with no heat number and no test report is just metal of unknown history.

A certified piece of aerospace material has four things:

• A specification and revision. For example AMS 4911 for Ti-6Al-4V plate, or ASTM B209 for general aluminum sheet and plate. The drawing or purchase order sets which one applies.
• A heat or lot number. The mill assigns it, and it ties the piece to one melt and one set of test results.
• A mill test report. Chemistry and mechanical test results for that heat or lot, issued by the producer.
• An unbroken trail. Every distributor, cutter or processor between the mill and you keeps the heat number on the material and passes the cert along.

Material specs commonly ordered

Order to the specification on the drawing, including the temper or condition. The table below lists common aerospace mill product specs and what each one covers. Always check which revision your drawing or contract cites, because SAE and ASTM revise these documents and the revision letter can matter at receiving inspection.

Two practical notes. First, AMS 5662 and AMS 5663 cover the same alloy in different conditions. 5662 is the softer solution treated condition that can be machined and then aged, while 5663 arrives already aged to full strength. Ordering the wrong one changes your heat treat plan. Second, older drawings may still call out AMS-QQ-A-250 or one of its alloy slash sheets. Several of those slash sheets have been cancelled or superseded, the 6061 sheet by AMS 4025, 4026 and 4027 plus ASTM B209, so confirm with your engineering group which current spec they will accept before you buy.

For background on each material family, see our library pages on titanium alloys, nickel superalloys and aluminum alloys.

Mill test reports and EN 10204 3.1

Ask for the mill test report for the actual heat or lot you receive, and make sure the heat number on the report matches the marking on the metal. That match is the most important single check on a material cert.

Many mills and distributors describe their certs using the EN 10204 document types:

• Type 2.2, test report. The manufacturer states the product conforms and gives results from non-specific inspection, meaning results representative of production, not of your delivery.
• Type 3.1, inspection certificate. Results come from specific inspection of the delivered product, and the certificate is validated by the manufacturer's authorized inspection representative, who is independent of the manufacturing department.
• Type 3.2, inspection certificate. Same as 3.1, plus validation by an inspector designated by the purchaser or a third party, usually by witnessing the tests.

For aerospace mill product, a cert showing specific results for the delivered heat, which is what a 3.1 provides, is the normal expectation.

When you read a mill test report, check:

• Specification and revision, alloy and temper match your purchase order
• Heat or lot number matches the material marking
• Chemistry and mechanical results fall inside the spec limits
• Melt practice is stated where the spec requires it, for example the vacuum arc remelt practice required for titanium plate to AMS 4911
• Country of melt is stated, which you need for DFARS specialty metals

Our library page on material certs and traceability goes further into reading certs line by line.

DFARS specialty metals: 252.225-7009 and 252.225-7008

If your contract is a DoD contract above the simplified acquisition threshold, titanium, many nickel alloys and many steels you buy may have to be melted or produced in the United States or a qualifying country. Ask for country of melt on every cert so you can prove it.

The DFARS defines specialty metals to include:

• Titanium and titanium alloys
• Zirconium and zirconium alloys
• Nickel and iron-nickel alloys where alloying metals other than nickel and iron exceed 10 percent
• Cobalt alloys where alloying metals other than cobalt and iron exceed 10 percent
• Steel above set limits for manganese, silicon or copper, or with more than 0.25 percent of elements such as chromium, nickel, molybdenum, vanadium or titanium

Aluminum is not on the list, which is one reason aluminum jobs rarely carry a melt restriction.

Two clauses do the work. DFARS 225.7003-5 prescribes 252.225-7008 when the contract requires delivery of specialty metals as end items, which is the clause you will see when the deliverable is the metal itself. It prescribes 252.225-7009 when the contract delivers aircraft, missile or space systems, ships, tank or automotive items, weapon systems or ammunition, or components of them, that contain specialty metals. That is the clause most buyers of machined parts encounter.

252.225-7009 has exceptions, including electronic components, a minimal content allowance of 2 percent by weight of the total specialty metal in the end item, and an exception for commercially available off-the-shelf items. The COTS exception does not cover specialty metal mill products such as bar, plate and sheet, so raw stock does not escape the requirement by being a catalog item. If your contract carries either clause, put it on the purchase order and require country of melt on the cert.

Keeping heat traceability through cutting

Traceability is only as good as the last saw cut. Every piece cut from a plate or bar has to leave the saw with the heat number on it and a copy of the cert behind it.

Require the cutter or distributor to:

• Transfer the heat or lot number, spec and alloy to every cut piece, by marking, tagging or labeling, before the next piece is cut
• Keep remnants marked so the next order from the same plate is still traceable
• Provide the original mill test report, or a legible copy, with each shipment
• Add its own certificate of conformance stating the material was cut from the heat on the cert

Distributors that hold AS9120, the aerospace quality standard for stocking distributors, are audited on exactly this kind of traceability. Machine shops working to AS9100 have a matching requirement for identification and traceability of product through their own processes.

At your dock, receiving inspection should confirm the marking against the cert before the material goes to stock. Our library page on receiving inspection covers how to set that up.

When surplus material is acceptable, and when it is not

Surplus is acceptable when it carries the same proof as new material: a matching mill cert, an intact heat marking and a known storage history. It is not acceptable when any link in that chain is missing, no matter how good the metal looks.

Surplus usually works well for:

• Prototypes, test articles, tooling and fixtures where your engineering group accepts it
• Flight or deliverable hardware when the cert, marking and spec revision all match the drawing
• Hard to find sizes or product forms where a remnant fits the part and new mill stock would mean a long wait or a large minimum

Walk away from surplus when:

• The heat number is missing, ground off, or does not match the cert
• The cert is a copy of a copy with illegible results, or shows changed values
• The spec revision or temper does not match your drawing and engineering will not accept the difference
• DFARS applies and the cert does not show country of melt
• The material has been reworked, heat treated or straightened by an unknown party after leaving the mill
• Your contract or prime requires material from an approved source list and the seller is not on it

Shops with certified excess stock can list it through our supplier signup.

Counterfeit and falsified material risk

The main risk with metal is not a fake brand name. It is a real-looking cert that does not describe the metal, either because results were falsified at the source or because paperwork was swapped somewhere in the chain.

The best known case in the space business shows how far this can reach. In 2019 the Justice Department announced that an Oregon aluminum extruder, Hydro Extrusion Portland, formerly Sapa Profiles, agreed to pay more than $46 million to resolve criminal charges and civil claims over a 19-year scheme of altering tensile test results and issuing false certifications. NASA linked the extrusions to the fairing separation failures that lost the Orbiting Carbon Observatory in 2009 and the Glory satellite in 2011.

Practical defenses:

• Buy from the mill, an authorized service center, or a distributor with a quality system that covers traceability
• Require a counterfeit materiel avoidance process from sellers outside the mill channel. SAE AS6174 is the standard written for materiel other than electronic parts.
• Screen GIDEP for alerts on the producer or product if you have access
• Verify a sample independently when the source is unfamiliar or the cert looks wrong

Our counterfeit parts avoidance guide covers the reporting side and the standards behind it.

PMI and other verification checks

Positive material identification, PMI, confirms chemistry on the actual piece. It is a fast check that the metal is the alloy the cert says it is, but it cannot confirm temper, heat treat condition or mechanical properties.

A sensible approach is PMI on every piece from an unfamiliar source, plus lab testing of a sample when the stakes are high or the cert raises questions. Put the verification you want in the request so it is planned and priced, not added at the dock.

Minimums, cut sizes and what drives lead time

Buy the size you need plus machining stock, and say so in the request. Most cost and delay in material comes from product form, size and quantity, not the alloy name.

• Cut to size versus full plate or bar. Distributors cut plate and bar to size, often with a minimum charge per order or per cut. A remnant that fits your blank can be much faster than a full mill product.
• Mill minimums. Ordering straight from a mill usually means mill quantities. Small buyers normally go through a service center or distributor.
• Thick sections and large rounds. Thick titanium plate, large diameter alloy 718 bar and some forging stock are made less often, so they are harder to find on the shelf.
• DFARS melt. A domestic or qualifying country melt requirement narrows the pool of stock.

We do not promise stock or lead times. A person reviews each request and replies within one business day with what we know, and rush requests are prioritized. Our library page on lead times and delivery covers how material fits into an overall schedule.

Export classification of material

Raw material can be export controlled, so classify it before shipping it or its technical data outside the United States. Do not assume a metal is uncontrolled because it is a commodity.

Many common mill products fall outside the specific entries on the Commerce Control List, but some do not. One example: under ECCN 1C202, titanium alloys capable of an ultimate tensile strength of 900 MPa or more at 20 degrees C, in the form of tubes or cylindrical solid forms with an outside diameter over 75 mm, are controlled. Large diameter round bar in a high strength titanium alloy can meet that description. ECCN 1C202 also has an entry for certain aluminum alloys in tube, solid or forging form.

The exporter is responsible for the classification. If you are shipping material to a foreign facility or supplier, have your export compliance group classify it, and put the classification on the order. If the drawing or the program itself is ITAR or CUI controlled, those rules apply to the data you send to the material supplier too. See our confidentiality page for how controlled data moves, and our controlled programs page for how we handle ITAR and CUI work.

What to put on the purchase order

Write the material requirement so a receiving inspector can check it line by line. Include:

• Alloy, temper or condition, and the specification with revision, for example AMS 4911 current revision or the revision your drawing cites
• Product form and size: plate thickness, bar diameter, cut length and width, and tolerances on the cut
• Quantity, and whether remnants or multiple heats are acceptable
• Certification required: mill test report for the delivered heat, EN 10204 type if your quality system uses it, and the seller's certificate of conformance
• Country of melt on the cert, and the DFARS clause if 252.225-7008 or 252.225-7009 applies
• Marking and traceability: heat number transferred to every piece
• Verification: PMI, hardness and conductivity, or lab testing if required
• Approved source requirements from your prime, if any
• Export classification if the material will leave the country
• Need date, and whether partial delivery helps

If the material is going straight to a machine shop, the same requirements should flow to that shop. Our aerospace CNC machining page covers what to require from the shop, and the aerospace RFQ checklist shows how material fits into a complete request.

How Aerospace Sourcing handles material requests

We are a sourcing service. We do not run a warehouse or a saw. We take your material request, look for certified stock or surplus that meets it, and manage it through delivery.

• One quote, one point of contact and one purchase order, even when the material comes from one source and the cutting or testing happens at another
• Your spec, cert, DFARS and traceability requirements flowed down to each supplier
• Certs checked against the material marking and your purchase order before shipment
• A certificate of conformance with every order, plus the mill test reports and other certs your request requires

If a piece of surplus does not have the paperwork to back it, we tell you and keep looking rather than ship it.

Request certified material

Send the alloy, spec, size and quantity through the certified material request form. It is preset for certified and surplus material, so it asks for the spec revision, cert type and DFARS requirement up front, which are the details that decide whether a piece of stock is usable. A person replies within one business day.

Questions

Related

• How to Buy Obsolete Parts Without Buying Counterfeits
• Aerospace CNC Machining for Space and Defense Buyers
• Aerospace RFQ Checklist for Machined and Fabricated Parts
• Sourcing Obsolete Aerospace Parts Safely

Sources

• SAE: AMS 4911 Titanium Alloy Sheet, Strip and Plate, 6Al-4V, Annealed
• voestalpine: Alloy 718 AMS 5662 and 5663
• SAE: AMS 4078 Aluminum Alloy Plate 7075-T7351
• SAE: AMS 4045 Aluminum Alloy Sheet and Plate 7075-T6, T651
• SAE: AMS 4027 Aluminum Alloy Sheet and Plate 6061-T6, T651
• Acquisition.gov: DFARS 252.225-7009
• Acquisition.gov: DFARS 252.225-7008
• Acquisition.gov: DFARS 225.7003-5 clause prescriptions
• Project Materials: EN 10204 certificate types
• US Department of Justice: aluminum extruder agrees to pay over $46 million
• Evident: considerations when using XRF for PMI
• Export Law Blog: titanium billets and ECCN 1C202