Henan Gnee New Material Co., Ltd. is one of the most reliable manufacturers and suppliers of 6061-T6 Aluminum Flat Bar in China. With abundant experience, we warmly welcome you to wholesale high quality 6061-T6 Aluminum Flat Bar in stock here from our factory. Good service and reasonable price are available.
What Is 6061-T6 Aluminum Flat Bar?
A 6061-T6 aluminum flat bar is a rectangular, solid extruded (or cold-finished) section in the 6xxx-series Al-Mg-Si system. "6061" is the alloy; "T6" is the temper, meaning the bar was solution heat treated and artificially aged to reach its highest usable strength. In the T6 condition it delivers about 310 MPa ultimate tensile strength at roughly one-third the weight of carbon steel, which is why it is the default structural aluminum bar for framing, brackets, machine bases, and busbars. 6061 is heat-treatable (unlike 1xxx, 3xxx, and 5xxx bars), so its strength comes from a controlled precipitation of Mg₂Si rather than from cold work alone. The flat shape makes it easy to bolt, drill, saw, and weld, and it anodizes cleanly for architectural and marine use.
Chemical Composition
| Element | Min % | Max % | Role / Function |
|---|---|---|---|
| Silicon (Si) | 0.40 | 0.80 | Forms Mg₂Si with Mg; primary precipitation-strengthening phase |
| Iron (Fe) | - | 0.70 | Impurity: kept low to protect surface and anodizing finish |
| Copper (Cu) | 0.15 | 0.40 | Raises strength and hardness; minor effect on corrosion |
| Manganese (Mn) | - | 0.15 | Minor; controls recrystallization |
| Magnesium (Mg) | 0.80 | 1.20 | With Si forming Mg₂Si, the core of T6 strength |
| Chromium (Cr) | 0.04 | 0.35 | Controls grain growth; improves toughness |
| Zinc (Zn) | - | 0.25 | Impurity: limited to avoid stress-corrosion sensitivity |
| Titanium (Ti) | - | 0.15 | Grain refiner |
| Other elements (each) | - | 0.05 | Total ≤ 0.15 |
| Aluminum (Al) | Remainder | Remainder | Base metal, ~97.9% |
Values per AA 6061 / ASTM B221 composition limits. Engineering chemistry is confirmed by optical emission spectrometry on each heat.
Mechanical Properties
| Temper | UTS MPa (ksi) | Yield MPa (ksi) | Elong % | Hardness |
|---|---|---|---|---|
| O (annealed) | 125 (18) | 55 (8) | 25 | ~30 HB |
| T6 | 310 (45) | 276 (40) | 12 | 95 HB (HRB 60) |
| T651 (stress-relieved) | 310 (45) | 276 (40) | 12 | 95 HB |
Physical & Thermal Properties
| Property | Value |
|---|---|
| Density | 2.70 g/cm³ (0.098 lb/in³) |
| Melting range | 582–652 °C (1080–1205 °F) |
| Modulus of elasticity | 68.9 GPa (10,000 ksi) |
| Thermal conductivity (T6) | 167 W/m·K |
| Electrical conductivity (T6) | 43% IACS |
| Coefficient of thermal expansion | 23.6 µm/m·°C (13.1 µin/in·°F) |
| Specific heat | 0.896 J/g·K |
| Poisson's ratio | 0.33 |
6061-T6 Aluminum Flat Bar Specifications Table
| Item | Range / Detail |
|---|---|
| Alloy & temper | 6061-T6, also T651 / T6511 / O on request |
| Thickness | 2–250 mm (0.08–9.8 in) |
| Width | 5–300 mm (0.2–11.8 in) |
| Length | 3000 / 6000 / 12000 mm, or cut-to-length |
| Edge | Square, rounded (R), or radius ends |
| Standards | ASTM B221 (extruded), ASTM B211 (cold-finished), AMS 4117 |
| Process | Extrusion, or plate-sawn/cold-finished bar |
| Finish | Mill, anodized, powder, PVDF, polished |
| Certification | Mill Test Certificate (EN 10204 3.1) on request |
Above ~150 mm thickness, extrusion is replaced by plate-sawing or forged routes.
Heat Treatment & Temper Guide
6061 is heat-treatable, so temper is a process, not a grade label. The T6 route used for our flat bar:
Solution heat treat: 530 ± 5°C (995°F) to dissolve Mg and Si into solid solution.
Quench: rapid water quench to retain the supersaturated structure.
Artificial aaging:175 ± 5°C (347°F) for 8 hours to precipitate Mg₂Si and reach full T6 strength.
For T651, the bar is stretched 1–3% after quenching to relieve residual stress before aging-this cuts distortion in machining and keeps long bars straight. T4 (solution + natural age) is softer and easier to form; O is fully annealed for maximum bend radius. We do not sell "T6" that has only been cold-worked-every T6 bar is age-certified by hardness and tensile check.
Equivalent Designations
| AA | UNS | EN | DIN | JIS | GB | ISO |
|---|---|---|---|---|---|---|
| 6061 | A96061 | EN AW-6061 (AlMg1SiCu) | 3.3211 (AlMgSi0.5Cu) | A6061 (JIS H4000) | 6061 (GB/T 3190) | AW-6061 |
Corrosion Resistance
Atmospheric: Good. The natural oxide film protects in rural, urban, and industrial air; no coating is needed for indoor structural use.
Marine: Good above the waterline. In salt spray, anodize or paint to stop pitting at cut edges and crevices.
Galvanic: Risk with steel or copper. Isolate with dielectric spacers or coat the joint; do not bolt bare to carbon steel.
Stress-corrosion cracking (SCC): Low risk for 6xxx in normal service. Avoid sustained loading above ~65 °C in chloride environments [To be confirmed].
Finish protection: Anodizing (Type II/III) or PVDF coating extends service life in coastal and architectural exposure.
Fabrication
Welding: 6061-T6 welds well by GTAW/TIG and GMAW. Use filler ER4043 for general joints or ER5356 where you need higher joint strength or a closer color match after anodizing. Be aware the heat-affected zone loses T6 temper (drops toward T4)-design the joint around the as-welded strength, or re-solution-treat and age the finished part if full T6 is required.
Machining: Good in T6. Use sharp carbide tooling, a generous rake angle, and flood coolant; T4 machines are slightly better if chips are the concern.
Formability: Poor in T6-bends only with a wide radius (minimum bend radius typically 3–4× thickness). For tight bends, specify T4 or O and heat-treat after forming.
Surface Finishes
| Finish | Description | Best for |
|---|---|---|
| Mill finish | Natural as-extruded, visible die lines | Structural, industrial, cost-sensitive |
| Anodized (Type II / III) | Sulfuric or hard anodize, clear/black/bronze | Marine, architectural, wear resistance |
| Powder coated | Electrostatic RAL color coat | Outdoor, UV exposure |
| PVDF-coated | Fluorocarbon, 20+ yr weatherability | Building façades |
| Polished / brushed | #4 / #6 / #7 mechanical finish | Decorative, trim |
| Sandblasted | Uniform matte texture | Industrial signage |
Quality Control & Delivery
Risk: Twist, uneven width, or off-spec hardness turns a flat bar into scrap the moment it hits the saw or the busbar joint-and the loss shows up after the buyer has already cut and drilled.
Action: Every 6061-T6 bar is checked for flatness and edge squareness against ASTM B221 limits, verified by Brinell hardness (95 HB typical) and a tensile pull per ASTM B557 on the heat, and confirmed for chemistry by optical emission spectrometry (PMI). Results are recorded on the Mill Test Certificate.
Standard: Dimensional per ASTM B221; chemistry per ASTM B221; tensile per ASTM B557; hardness per ASTM E10; MTC to EN 10204 3.1.
Result: You receive a bar that seats flat, is machine-size, and comes with traceable proof-not a promise.
Delivery: On order we confirm the drawing and temper within one business day and lock the size in the production plan. Standard 6061-T6 flat bar ships in 15–30 days; cut-to-length and special tempers are confirmed at quotation. If a batch fails flatness or hardness at final inspection, we isolate and replace it before dispatch-you are not left carrying a rejected lot. Contact now to start a quote with your drawing attached.
Applications
Structural framing: Machine guards, racking, and light frames-needs T6 strength at low weight.
Brackets & gussets: Bolted supports where flatness and hole pattern must hold.
Busbars & conductors: 43 % IACS conductivity carries current where steel cannot; flat face aids bolted contact.
Marine topside: Rails, ladder stringers, and equipment mounts above the waterline (anodized for salt spray).
Truck & trailer frames: Lightweight structural members, outriggers, and deck supports.
Machine bases & fixtures: Jigs, guide rails, and tooling plates needing stable, machinable stock.
Heat sinks: 167 W/m ·K conductivity dissipates heat in electrical enclosures.
Architectural trim: Anodized reveal strips and balustrade infill.
6061-T6 vs. Other Aluminum Alloys
| Alloy / Temper | UTS MPa | Yield MPa | Elong % | Density in g/cm³ | Cond % IACS | Relative cost | Why pick it |
|---|---|---|---|---|---|---|---|
| 6061-T6 | 310 | 276 | 12 | 2.70 | 43 | 1.0 (ref) | Balanced strength, weld, corrosion |
| 6063-T5 | 185 | 145 | 12 | 2.70 | 53 | ~0.95 | Architectural, smoother surface, lower strength |
| 6082-T6 | 310 | 270 | 12 | 2.70 | 40 | ~1.05 | EU-preferred, slightly higher Mn, equal strength |
| 5052-H32 | 215 | 160 | 12 | 2.68 | 35 | ~1.10 | Marine/formable, non-heat-treatable |
| 7075-T6 | 570 | 505 | 11 | 2.81 | 33 | ~1.8 | Max strength, lower corrosion & weldability |
Relative cost is indicative and market-dependent; confirm against the current mill quotation.
Why Choose GNEE
18 years of export, documented traceability. Every 6061-T6 flat bar ships with a Mill Test Certificate (EN 10204 3.1) showing heat chemistry, tensile, and hardness-not a generic certificate.
Size flexibility without a warehouse full of dead stock. We cut 2–250 mm thickness and 5–300 mm width to your length (3 / 6 / 12 m or cut-to-length), so you buy the bar, not the remnant.
Predictable lead time. Standard 6061-T6 flat bar is produced and dispatched in 15–30 days; special tempers and finishes are quoted up front with a confirmed date, not "soon."
Export-grade packaging. PE-wrap per bar, steel or PET strapping into bundles, then fumigated wooden crates or pallets with moisture-proof liner-bars arrive straight and unscratched.
Technical selection support. If your drawing calls for a bend radius T6 that cannot be made or a weld that needs full strength, our team flags the temper or filler change before production, not after delivery.
Contact now for a quotation, MTC sample, and current lead time on your 6061-T6 flat bar requirement.
FAQ
Q1. What is the difference between 6061-T6 and 6061-T651?
A: Same strength. T651 is stretched 1–3% after quenching to remove residual stress, so it stays straighter and distorts less in machining. Choose T651 for precision-cut or long bars.
Q2. Can I weld 6061-T6 and keep the full 310 MPa strength?
A: The weld joint itself drops toward T4 (~240 MPa) in the heat-affected zone. For most brackets and frames that is acceptable by design; if you need full T6 at the weld, the finished part must be re-solution-treated and aged.
Q3. What thickness and width can you supply?
A: Extruded 6061-T6 flat bar from 2 mm to 250 mm thick and 5 mm to 300 mm wide, cut to 3 / 6 / 12 m or your length. Above ~150 mm thickness, we switch to plate-sawn or forged routes-confirm availability [To be confirmed].
Q4. How straight is the bar (twist / flatness)?
A: Checked against ASTM B221 dimensional limits; typical twist and flatness are recorded on the MTC. Tell us your allowable twist per meter, and we will screen it.
Q5. Will anodizing match the weld color?
A: Use ER5356 filler if the welded part will be anodized-it colors closer to the base than ER4043. Note the HAZ will still anodize slightly differently; that is normal for 6061-T6.
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