6061-T6 & 7075-T651 Aluminum MTR Checklist: Why Aluminum is Exempt from DFARS 252.225-7009 Specialty Metals + Conductivity/Temper Checks

Editorial & Regulatory Scope Notice: This technical guide is published as an administrative quality-control reference for AS9100 Rev D and ISO 9001 precision machine shops inspecting wrought aluminum bar, plate, sheet, and extrusions (UNS A96061 / UNS A97075). Statutory citations reference public US federal law (10 U.S.C. § 4863, DFARS 252.225-7009, DFARS 252.225-7001, DFARS 252.225-7021). No copyrighted SAE/AMS or ASTM specification tables are reproduced; inspectors must verify actual values against their facility's licensed specification revision, Purchase Order (PO) flow-downs, and the requirement rows printed on the mill certificate. Final material release rests solely with authorized human QA personnel.

Every week in aerospace and defense CNC job shops, one of two costly aluminum receiving mistakes happens on the loading dock:

1. The False Quarantine Mistake: A receiving inspector quarantines a perfectly conforming bundle of 6061-T651 or 7075-T651 plate—halting spindle production for days—because the MTR shows melt/cast origin in South Africa, Bahrain, Austria, or South Korea and the PO boilerplate includes DFARS 252.225-7009 (Specialty Metals).
2. The Real Origin / Temper Mistake: Conversely, a shop assumes "aluminum never has origin restrictions," ignoring DFARS 252.225-7001 (Buy American), DFARS 252.225-7021 (Trade Agreements Act), or U.S. sanctions/tariff origin flow-downs—or accepts non-stress-relieved T6 in place of stretched T651 / T7351 aerospace plate without checking Eddy-Current Electrical Conductivity (% IACS)!

Here is the exact regulatory truth and 10-point MTR verification checklist for 6061 and 7075 aluminum.

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• Launch the ProvaTrace DFARS 252.225-7009 & MTR Bounding-Box Validator →
  Select Aluminum Alloys (6061 / 7075 / 2024) in the free validator to generate a documented statutory 10 U.S.C. § 4863 Specialty Metals Exemption memo—plus automatic alerts for Buy American / TAA PO flow-downs and MTR chemistry/mechanical bounding-box verification.

1. Why 6061 & 7075 Aluminum Are EXEMPT from DFARS 252.225-7009 Specialty Metals

Look directly at the federal statutory definition codified in 10 U.S.C. § 4863(l)(1) and implemented verbatim in DFARS 252.225-7009(a):

Under US law, "Specialty Metal" covers only four specific metallurgical categories:

1. Steel (exceeding specified alloy limits, including >0.25% Aluminum as an alloying element inside steel—NOT aluminum-base alloys!);
2. Base metal alloys of Nickel, Iron-Nickel, and Cobalt (containing >10% other alloying metals except iron);
3. Titanium and Titanium Alloys; and
4. Zirconium and Zirconium Base Alloys.

What This Means at Receiving Inspection

• Aluminum and Aluminum Base Alloys (6061, 7075, 2024, 5052, 5083, MIC-6, etc.) are NOT Specialty Metals under 10 U.S.C. § 4863 / DFARS 252.225-7009.
• Why do defense prime POs stamped "DFARS 252.225-7009 Applies" land on aluminum orders anyway? Because ERP procurement systems at primes and Tier-1 contractors automatically attach standard defense terms & conditions to every line item on a military contract, relying on the clause's self-limiting text ("...any specialty metal...").
• Wait—Before Releasing Foreign Aluminum, Check These 3 Actual Origin Clauses!
  Just because DFARS 252.225-7009 does not apply to aluminum does NOT mean country of origin never matters on your PO:
  • Buy American Act / Balance of Payments (FAR 52.225-1 / DFARS 252.225-7001) & Trade Agreements Act (DFARS 252.225-7021): Govern end-item manufacture and domestic/qualifying/designated-country component thresholds when your shop delivers finished defense/federal end items.
  • Russian / Sanctioned Aluminum Prohibitions & Section 232 / Customs Rules: Federal sanctions and prime-contractor compliance declarations strictly prohibit or require tracing primary aluminum smelted or cast in Russia (even if rolled into plate in a third country!). Always check Country of Smelt / Cast as well as rolling country when sanctions compliance clauses appear on the PO.
  • Prime Customer "Domestic / Approved Mill Only" Engineering Notes: Structural airframe plate (7075-T7351, 7050-T7451, 2024-T351) frequently invokes prime-specific Approved Mill Source Lists (e.g., Kaiser, Constellium, Arconic, AMAG, Hulamin—depending on the prime's qualified plate schedule). Always check PO quality notes!

2. The Temper Suffix Trap: T6 vs. T651 vs. T6511 vs. T7351

On aluminum MTRs, missing two digits at the end of the temper callout leads directly to warped thin-wall housings or stress-corrosion cracking rejections:

3. Eddy-Current Electrical Conductivity (% IACS) & Lot Acceptance Checks on 7075

When inspecting 7000-series aerospace aluminum (7075-T73, 7075-T7351, 7075-T7651, 7050-T7451) MTRs, tensile strength and hardness alone cannot prove proper over-aging!

Because an under-aged lot and an over-aged lot of 7075 can exhibit identical Rockwell B / Brinell hardness on either side of the aging curve peak, aerospace specifications require Lot Acceptance Testing for Stress-Corrosion Resistance combining:

1. Mechanical Yield / Tensile Strength Verification (checking both minimum AND, on over-aged tempers, maximum yield strength ceilings or yield-to-conductivity relationships); AND
2. Electrical Conductivity (% IACS — International Annealed Copper Standard, per AMS 2658 / eddy-current testing): As 7075 over-ages from -T6 into -T73, precipitates coarsen out of solid solution and electrical conductivity rises (for example, 7075-T73XX requires significantly higher % IACS conductivity than 7075-T6XX).

Inspector Rule: On every 7075-T73XX or 7075-T76XX aerospace MTR, verify both % IACS electrical conductivity AND tensile/yield values against the printed specification limits on the cert!

4. Thickness-Dependent Mechanical Limits & Clad vs. Bare Sheet Traps

Two additional pitfalls catch receiving inspectors on aluminum EN 10204 3.1 / mill certs:

1. Thickness-Bracketed Minimum Properties: A 0.500" thick 7075-T651 plate and a 3.500" thick 7075-T651 plate made to the exact same specification have different minimum UTS, Yield, and Elongation requirements due to quench-rate mass effects through thick sections (and frequently shift from longitudinal L to long-transverse LT / short-transverse ST test orientations). Always check that the MTR's printed min/max row corresponds to the exact ordered thickness bracket.
2. Alclad vs. Bare Sheet/Plate (Alclad 2024 / Alclad 7075 vs. Bare): Aerospace sheet and thin plate come in both Bare and Alclad (metallurgically bonded pure-aluminum corrosion-protective surface cladding, which has slightly lower composite tensile/yield minimums and looks shinier/softer on outer faces). Mixing Bare and Alclad fails anodize appearance, conductivity, and AS9102 FAI verification immediately.

5. 10-Point AS9100 Receiving Checklist for 6061 & 7075 Aluminum

• 1. Product Form, Spec & Exact Temper Match: Confirm Rolled/Cold-Finished Bar vs. Extruded Bar vs. Plate vs. Sheet (and Bare vs. Alclad), exact temper (T6 vs. T651 vs. T6511 vs. T7351), and dimensions match PO and Continuous Ink-Jet Stencils printed directly on the metal.
• 2. Original Producing Mill MTR (EN 10204 3.1 / Mill Test Report): Verify cast/heat number and inspection lot number trace unbroken from the aluminum mill's test report through the service center's saw-cut tag.
• 3. Cast Chemistry Verification (Si, Fe, Cu, Mn, Mg, Cr, Zn, Ti + Others Each / Total): Verify every element—including "Other Elements, Each" (commonly <= 0.05%) and "Other Elements, Total" (commonly <= 0.15%)—falls within printed MTR limits.
• 4. Thickness-Bracketed Mechanical Properties (MPa <-> ksi): Normalize MPa to ksi (1 MPa = 0.145038 ksi) and verify UTS, 0.2% Yield (both min and max where applicable!), and Elongation for the exact purchased thickness/diameter range and test direction (L / LT / ST).
• 5. Electrical Conductivity (% IACS) & SCC Lot Acceptance (7075 / 7050): Confirm % IACS eddy-current conductivity values pass printed specification floors on all -T73XX, -T74XX, and -T76XX aerospace lots.
• 6. Ultrasonic Inspection Class (Thick Aerospace Plate/Bar): When aerospace specs or PO notes invoke immersion ultrasonic inspection (e.g., AMS-STD-2154 Class A or B on thick structural plate), confirm explicit UT certification is attached.
• 7. Regulatory Origin Sanity Check:
  • Document DFARS 252.225-7009 Not Applicable (Non-Specialty Metal per 10 U.S.C. § 4863) so auditors never question foreign-melted aluminum when only 252.225-7009 appears on the PO;
  • AND verify Buy American (252.225-7001), TAA (252.225-7021), non-Russian primary smelt compliance, and Prime Approved Mill lists if flowed down!
• 8. Protective PVC Interleaving & Surface Corrosion Check: Inspect polished/aerospace sheet and plate for water-stain corrosion (white rust), transit scratches, and intact stencil ink before sawing.
• 9. Stencil Transfer Protocol: If sawing a 48" x 144" plate into blanks, ensure shop procedure transfers Heat/Lot IDs to cut remnants before the stenciled edge goes into the chip hopper.
• 10. QA Sign-Off & 10-Year Heat-Lot Vault Indexing: Record internal Receiving Lot #, apply release label, and store the MTR indexed by Cast/Lot #, PO #, and Work Order #.

Stop Second-Guessing DFARS Exemptions & MTR Math at the Receiving Dock

Whether your inspector is checking if 6061-T651 needs a DFARS melt waiver, converting metric MPa plate certs from European rolling mills into ksi, or verifying % IACS conductivity on 7075-T7351 airframe hog-outs, manual paperwork slows spindles down.

ProvaTrace gives AS9100 and ISO 9001 machine shops instant receiving clarity:

• Deterministic 10 U.S.C. § 4863 Statutory Engine: Automatically identifies non-specialty metals like 6061 and 7075 aluminum (generating an audit-ready statutory citation note for your receiving file) while flagging Buy American / TAA and specialty-metal melt rules accurately.
• Side-by-Side Bounding-Box MTR Verification: Highlights chemistry (Others Each / Total), thickness-specific tensile/yield (MPa <-> ksi), and % IACS conductivity cells right on the PDF for 10-second human QA sign-off.
• 1-Click AS9102 Form 2 & Customer Cert Turnover Packs: Build clean customer material cert binders and FAI tables in seconds.

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Disclaimer: ProvaTrace provides administrative document-extraction and deterministic comparison software requiring authorized human QA inspector verification. Never upload ITAR (22 CFR 120–130) or DoD CUI technical blueprints.