Extruded bar
Lowest cost on standard sizes; good straightness and surface.
Structural busbar guide
6082 Aluminium Busbar for Load-Bearing Conductors
6082 is the strongest of the common 6xxx alloys used as busbar. Its conductivity is lower (about 42 % IACS in T6, against 55 – 61 % for 6101 and 1350), so it is chosen when the bar must also act as a structural member: long unsupported spans, high short-circuit forces, vibration or bolted frames. This guide shows when that trade-off is worth making and how to size and specify 6082 busbar.
- Alloy
- 6082 (EN AW-6082, A96082)
- Tempers
- T4, T5, T6
- Conductivity
- ≈ 42 % IACS in T6
- Standards
- EN 755-2 · EN 755-5 · ASTM B221
When does a busbar need 6082?
Most busbars are limited by heat, not by strength. 6082 only makes sense when strength or stiffness, rather than temperature rise, is the limiting design requirement.
6082 contains more silicon and magnesium than 6063 or 6101, plus up to 1 % manganese. Manganese refines the grain and gives 6082 its high strength in thick sections, but manganese in solid solution is also one of the most damaging elements for electrical conductivity. That is why a 6082-T6 bar conducts roughly 25 – 30 % less than a 6101-T6 bar of the same size.
In return, 6082-T6 offers roughly 1.5 times the yield strength of 6063-T6 and more than double the minimum for 6101-T61. For a bar spanning between widely spaced insulators, the deflection and stress under short-circuit electromagnetic forces can govern the design, and a stronger bar means fewer supports. In traction, marine and mobile equipment, vibration and shock push in the same direction.
6082 chemical composition (wt %)
| Element | Minimum | Maximum | Effect |
|---|---|---|---|
| Silicon (Si) | 0.70 | 1.30 | Forms Mg2Si; excess Si adds strength |
| Iron (Fe) | — | 0.50 | Impurity |
| Copper (Cu) | — | 0.10 | Impurity |
| Manganese (Mn) | 0.40 | 1.00 | Grain control and strength; largest conductivity penalty |
| Magnesium (Mg) | 0.60 | 1.20 | Main strengthening element |
| Chromium (Cr) | — | 0.25 | Grain control; lowers conductivity |
| Zinc (Zn) | — | 0.20 | Impurity |
| Titanium (Ti) | — | 0.10 | Grain refiner |
| Others, each / total | — | 0.05 / 0.15 | |
| Aluminium (Al) | Remainder | About 95.2 – 98.3 % |
Limits follow EN 573-3 (EN AW-6082, AlSi1MgMn) and the Aluminum Association registration. Equivalent designations: UNS A96082, Werkstoff 3.2315, former DIN AlMgSi1 and former British HE30.
Strength and conductivity of 6082 busbar
Mechanical minimums below are from EN 755-2 for extruded bar and profiles in the thickness bands most used for busbar. Values vary with section thickness and product form, so check the band that matches your bar.
| Temper | Product / thickness | Tensile Rm min | Yield Rp0.2 min | Elongation A min |
|---|---|---|---|---|
| T4 | Bar ≤ 25 mm | 205 MPa | 110 MPa | 14 % |
| T5 | Profiles ≤ 5 mm | 270 MPa | 230 MPa | 8 % |
| T6 | Bar ≤ 20 mm | 295 MPa | 250 MPa | 8 % |
| T6 | Profiles 5 – 25 mm | 310 MPa | 260 MPa | 10 % |
| Property (T6, typical) | Value |
|---|---|
| Electrical conductivity | ≈ 42 % IACS (≈ 24 MS/m) |
| Resistivity at 20 °C | ≈ 41 nΩ·m |
| Thermal conductivity | ≈ 160 – 170 W/m·K |
| Brinell hardness | ≈ 90 – 95 HB |
| Density | 2.70 g/cm³ |
| Modulus of elasticity | ≈ 70 GPa |
| Coefficient of thermal expansion | ≈ 23 µm/m·°C |
Conductivity in the T4 and O conditions is higher than in T6, but strength falls with it. If you need a guaranteed minimum (for example ≥ 24 MS/m), write it on the order and ask for a measured value on the certificate.
Common sizes, weight and DC resistance
The table uses density 2.70 g/cm³ and conductivity 42 % IACS (6082-T6) to give mass and DC resistance per metre at 20 °C. Compare with the same sizes in 6063 (≈ 53 % IACS) on our 6063 busbar guide: 6082 has about 25 % more resistance for the same section.
| Size t × w (mm) | Area (mm²) | Mass (kg/m) | DC resistance (µΩ/m) |
|---|---|---|---|
| 3 × 25 | 75 | 0.203 | 547.3 |
| 4 × 40 | 160 | 0.432 | 256.6 |
| 5 × 30 | 150 | 0.405 | 273.7 |
| 5 × 50 | 250 | 0.675 | 164.2 |
| 6 × 60 | 360 | 0.972 | 114.0 |
| 8 × 80 | 640 | 1.728 | 64.1 |
| 10 × 50 | 500 | 1.350 | 82.1 |
| 10 × 80 | 800 | 2.160 | 51.3 |
| 10 × 100 | 1000 | 2.700 | 41.0 |
| 12 × 120 | 1440 | 3.888 | 28.5 |
| 15 × 150 | 2250 | 6.075 | 18.2 |
| 20 × 200 | 4000 | 10.800 | 10.3 |
Because power loss is I²R, a 6082 bar carrying the same current as a 6101 bar of the same section dissipates about 30 % more heat. Either accept a lower rating, increase the section, or use 6082 only for the structural part of the run and a higher-conductivity grade elsewhere.
Forms, sizes and processing
Typical supply range
- Extruded flat bar
- Thickness about 2 – 40 mm, width about 10 – 200 mm
- Plate-cut bar
- Thick and wide sections sawn from 6082-T651 plate, up to about 250 mm thick
- Length
- Mill lengths up to about 6 m or cut to length
- Edges
- Square, radiused or full-round
- Tolerances
- EN 755-5 for extruded rectangular bar; tighter by machining
- Processing
- Sawing, drilling, tapping, milling, bending, plating and insulation coating
Plate-cut bar
Used for very wide or thick blocks, or short runs of unusual sizes; T651 plate keeps the bar flat when machined.
Machined connectors
Tapped blocks, clamps and terminals benefit from 6082's machinability and thread strength.
Bending, machining and joints
- Bending: 6082-T6 is less ductile than 6063 or 6101. Allow larger inside radii (typically 2 – 3 × thickness flatwise) or bend in T4 and age afterwards. Bend across, not along, any visible extrusion lines.
- Machining: very good in T6, with short chips. Ideal for tapped holes and precise contact faces.
- Bolted joints: the higher strength resists creep under bolt load better than 1350 or 6063, but still use conical spring washers and contact grease on aluminium-to-aluminium joints.
- Plating: tin, silver or nickel at contact areas after a zincate pre-treatment. Plated joints keep contact resistance low over long service.
- Welding: MIG or TIG with ER4043 or ER5356; the heat-affected zone loses a large part of its T6 strength, so weld away from highly stressed spans.
- Corrosion: good general resistance. Avoid direct contact with bare copper in humid service; use plated surfaces or bimetallic transition pieces.
6082 compared with 6101, 6063 and 1350
| Grade and temper | Conductivity | Specified minimum yield strength | Relative heat at same current and size |
|---|---|---|---|
| 1350-H111 | ≥ 61 % IACS | 24 MPa | 1.00 |
| 6101-T61 (3.2 – 19 mm) | ≥ 57 % IACS | 103 MPa | 1.07 |
| 6101-T6 (3.2 – 12.7 mm) | ≥ 55 % IACS | 172 MPa | 1.11 |
| 6063-T6 (≤ 10 mm, EN 755-2) | ≈ 53 % IACS typical | 170 MPa | 1.15 |
| 6082-T6 (bar ≤ 20 mm, EN 755-2) | ≈ 42 % IACS typical | 250 MPa | 1.45 |
Relative heat is the ratio of resistance to that of 1350 at 61 % IACS, for the same section and current. Yield values are specified minimums from ASTM B317 (1350, 6101) and EN 755-2 (6063, 6082).
The table shows why 6082 is a specialist choice. If a 6101-T6 bar is strong enough, it will run cooler and waste less energy. Choose 6082 when the bar would otherwise need extra supports or a separate structural member.
How to specify 6082 busbar
- Section and lengthThickness × width, edge form and length, or a fabrication drawing.
- Temper and standardFor example "EN AW-6082 T6 to EN 755-2, tolerances to EN 755-5".
- Electrical requirementMinimum conductivity if it matters to your rating, measured at 20 °C.
- Finish and processingPlating, insulation, holes, threads and bends.
- Documents and deliveryEN 10204 3.1 certificate, delivery terms (EXW, FOB, CIF or DAP) and packing.
References and standards
- EN 755-2 – Extruded rod/bar, tube and profiles: mechanical properties
- EN 755-5 – Extruded rectangular bar: tolerances on dimensions and form
- EN 573-3 – Chemical composition and form of wrought products
- ASTM B221 – Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
- The Aluminum Association – Aluminum Standards and Data, electric conductor property limits (Table 16.3)
6082 aluminium (aluminum) busbar: FAQ
What is the conductivity of 6082 busbar?
About 42 % IACS (around 24 MS/m) in T6, compared with 55 – 59.5 % IACS minimum for 6101 tempers and 61 % for 1350.
Is 6082 a good busbar material?
It is a good structural conductor but a poor choice where losses and temperature rise dominate. Use it where strength, stiffness or vibration resistance matter more than conductivity.
What is the difference between 6082 and 6101 busbar?
6101 is designed as a conductor and its conductivity is guaranteed by ASTM B317. 6082 is a structural alloy that is roughly 50 % stronger in T6 but about 25 – 30 % less conductive.
Can 6082-T6 busbar be bent?
Yes, with generous radii of about 2 – 3 × thickness. For tight bends, form it in T4 and age to T6 afterwards.
What are the equivalents of 6082?
EN AW-6082 (AlSi1MgMn), UNS A96082, Werkstoff 3.2315, former DIN AlMgSi1 and former British HE30.
Need a busbar that also carries load?
Send the section, span, current and environment. Metline will suggest 6082 or a better-conducting grade and quote accordingly.
