6060
Lowest strength, finest surface and best decorative anodising. Use for trim fittings, light-duty spacers and visible hardware.
Marine bar stock
Marine Grade 6060, 6005A, 6082 and 6061 Aluminium Hexagonal Bar
Heat-treatable 6xxx hex bar is the standard stock for turned marine fittings, couplings, nuts and spacers that need more strength and better machinability than 5xxx alloys. 6060 is the softest and easiest to anodise, 6005A and 6061 sit in the middle, and 6082-T6 is the strongest. Metline supplies all four grades in T4, T5 and T6 conditions, cut to length with EN 10204 3.1 certificates, to buyers worldwide.
- Alloys
- 6060 · 6005A · 6082 · 6061
- Tempers
- O, T4, T5, T6 (and stretched variants)
- Across flats
- about 10 – 120 mm
- Standard
- EN 755-2 · EN 755-6
Choosing a 6xxx hex bar for marine fittings
A hexagon gives a turned part its spanner flats for free. Marine engineers use hex bar for hose tails, union nuts, through-hull adaptors in non-immersed positions, cable glands, stand-offs, threaded spacers and the bodies of deck hardware. The 6xxx (Al-Mg-Si) alloys dominate this work because they machine cleanly in T6 temper, anodise well and offer two to three times the proof strength of soft 5xxx alloys.
The four grades on this page cover the full range of 6xxx strength. They share the same basic metallurgy (magnesium silicide precipitates formed by solution heat treatment and ageing), but they differ in how much silicon, magnesium and manganese they contain, and that changes strength, extrudability and surface quality.
For parts on deck, in the superstructure or inside the hull, any of them performs well, particularly when anodised. For parts permanently wetted by seawater, the 5xxx alloys (5083, 5086, 5A02) are the more conservative choice, and 6xxx parts should be anodised or painted and electrically isolated from stainless steel and bronze.
6005A
Medium strength with good extrudability. A sensible upgrade from 6060 where loads are moderate.
6061
The ASTM-world general-engineering grade: good strength, excellent machinability and anodising. Standard in North America and Asia.
6082
Highest strength of the group and the European structural standard. Choose for loaded fittings and fasteners.
Chemical composition (wt %)
Registered limits per EN 573-3 and the Aluminum Association. Some older tables mix up 6060 with 6063 (which has more magnesium) or show 6082 with chromium as a required element; the values below are the registered ones.
| Element | 6060 | 6005A | 6082 | 6061 |
|---|---|---|---|---|
| Silicon (Si) | 0.30 – 0.60 | 0.50 – 0.90 | 0.70 – 1.30 | 0.40 – 0.80 |
| Iron (Fe) | 0.10 – 0.30 | ≤ 0.35 | ≤ 0.50 | ≤ 0.70 |
| Copper (Cu) | ≤ 0.10 | ≤ 0.30 | ≤ 0.10 | 0.15 – 0.40 |
| Manganese (Mn) | ≤ 0.10 | ≤ 0.50 | 0.40 – 1.00 | ≤ 0.15 |
| Magnesium (Mg) | 0.35 – 0.60 | 0.40 – 0.70 | 0.60 – 1.20 | 0.80 – 1.20 |
| Chromium (Cr) | ≤ 0.05 | ≤ 0.30 | ≤ 0.25 | 0.04 – 0.35 |
| Zinc (Zn) | ≤ 0.15 | ≤ 0.20 | ≤ 0.20 | ≤ 0.25 |
| Titanium (Ti) | ≤ 0.10 | ≤ 0.10 | ≤ 0.10 | ≤ 0.15 |
| Others, each / total | ≤ 0.05 / ≤ 0.15 | ≤ 0.05 / ≤ 0.15 | ≤ 0.05 / ≤ 0.15 | ≤ 0.05 / ≤ 0.15 |
| Aluminium (Al) | Remainder | Remainder | Remainder | Remainder |
6005A additionally requires Mn + Cr of 0.12 – 0.50 %. The manganese in 6082 and the chromium in 6061 control grain structure, which is why those two grades keep their strength well in larger sections, while 6060 can show a coarser grain and lower strength in thick bar.
Mechanical properties by alloy and temper
Minimum values from EN 755-2 for extruded bar, where D is the across-flats dimension. Elongation is A (5.65√S0); thin bars tested on A50 mm gauge show slightly lower values.
| Alloy-temper | Size D (mm) | Tensile Rm (min) | Proof Rp0.2 (min) | Elongation A |
|---|---|---|---|---|
| 6060-T4 | ≤ 150 | 120 MPa | 60 MPa | ≥ 16 % |
| 6060-T5 | ≤ 150 | 160 MPa | 120 MPa | ≥ 8 % |
| 6060-T6 | ≤ 150 | 190 MPa | 150 MPa | ≥ 8 % |
| 6005A-T6 | ≤ 25 | 270 MPa | 225 MPa | ≥ 10 % |
| 6005A-T6 | > 25 – 50 | 270 MPa | 225 MPa | ≥ 8 % |
| 6005A-T6 | > 50 – 100 | 260 MPa | 215 MPa | ≥ 8 % |
| 6082-O | ≤ 200 | ≤ 160 MPa | ≤ 110 MPa | ≥ 14 % |
| 6082-T4 | ≤ 200 | 205 MPa | 110 MPa | ≥ 14 % |
| 6082-T6 | ≤ 20 | 295 MPa | 250 MPa | ≥ 8 % |
| 6082-T6 | > 20 – 150 | 310 MPa | 260 MPa | ≥ 8 % |
| 6082-T6 | > 150 – 200 | 280 MPa | 240 MPa | ≥ 6 % |
| 6082-T6 | > 200 – 250 | 270 MPa | 200 MPa | ≥ 6 % |
| 6061-O | ≤ 200 | ≤ 150 MPa | ≤ 110 MPa | ≥ 16 % |
| 6061-T4 | ≤ 200 | 180 MPa | 110 MPa | ≥ 15 % |
| 6061-T6 | ≤ 200 | 260 MPa | 240 MPa | ≥ 8 % |
Typical properties are usually 10 – 20 % above these minimums. For reference, 6061-T6 typically reaches about 310 MPa tensile and 275 MPa proof strength, and 6082-T6 about 330 – 340 MPa and 300 MPa.
Physical properties (T6, typical)
- Density
- 2.70 g/cm³ for all four alloys
- Elastic modulus
- about 69 – 70 GPa
- Thermal conductivity
- 6060 about 200 W/m·K; 6005A about 185; 6082 about 175; 6061 about 167
- Coefficient of thermal expansion
- about 23.4 – 23.6 µm/m·°C
Tempers you will see on marine hex bar
| Temper | What it means | Typical use |
|---|---|---|
| O | Fully annealed, softest condition | Cold heading, swaging; re-heat-treat afterwards for strength |
| T4 | Solution heat-treated and naturally aged | Forming before final ageing; moderate strength |
| T3511 | Solution treated, stretched to relieve stress, naturally aged | Same strength class as T4 with better straightness |
| T5 | Cooled from the extrusion press and artificially aged | Economical 6060 bar for light-duty parts |
| T6 | Solution heat-treated and artificially aged | Standard choice for machined fittings |
| T6511 / T8511 | T6-strength bar stretched for stress relief (T8511 includes cold work before ageing) | Precision turning where distortion must be minimised |
Sizes and weights
Supply range
- Across flats
- About 10 – 120 mm; larger sizes by arrangement
- Length
- 1 – 6 m standard, longer by arrangement; cut-to-length pieces
- Finish
- Mill finish; drawn or peeled for tighter tolerances; anodised on request
Hex bar weight per metre = 0.866 × s² × 2.70 / 1,000 (s = across flats in mm).
| Across flats (mm) | kg per metre | kg per 3 m bar | kg per 6 m bar |
|---|---|---|---|
| 10 | 0.234 | 0.70 | 1.4 |
| 12 | 0.337 | 1.01 | 2.0 |
| 14 | 0.458 | 1.37 | 2.7 |
| 17 | 0.676 | 2.03 | 4.1 |
| 19 | 0.844 | 2.53 | 5.1 |
| 22 | 1.13 | 3.40 | 6.8 |
| 24 | 1.35 | 4.04 | 8.1 |
| 27 | 1.70 | 5.11 | 10.2 |
| 30 | 2.10 | 6.31 | 12.6 |
| 32 | 2.39 | 7.18 | 14.4 |
| 36 | 3.03 | 9.09 | 18.2 |
| 41 | 3.93 | 11.79 | 23.6 |
| 46 | 4.95 | 14.84 | 29.7 |
| 50 | 5.85 | 17.54 | 35.1 |
| 55 | 7.07 | 21.22 | 42.4 |
| 60 | 8.42 | 25.25 | 50.5 |
| 70 | 11.46 | 34.37 | 68.7 |
| 80 | 14.96 | 44.89 | 89.8 |
| 100 | 23.38 | 70.15 | 140.3 |
| 120 | 33.67 | 101.01 | 202.0 |
Hex bar tolerances
All four alloys fall in the easier-to-extrude group of EN 755-6. Across-flats tolerances usually applied:
| Across flats (mm) | Permitted deviation (mm) |
|---|---|
| over 8 to 18 | ±0.22 |
| over 18 to 25 | ±0.25 |
| over 25 to 40 | ±0.30 |
| over 40 to 50 | ±0.35 |
| over 50 to 65 | ±0.40 |
| over 65 to 80 | ±0.45 |
| over 80 to 100 | ±0.55 |
| over 100 to 120 | ±0.65 |
| over 120 to 150 | ±0.80 |
| over 150 to 180 | ±1.00 |
| over 180 to 220 | ±1.15 |
Form
- Corner radius
- Up to about 1.5 mm on small bars, 3 mm on 80 – 120 mm bars
- Straightness
- About 0.8 mm per 300 mm up to 80 mm
- Twist
- About 1 – 2 mm per metre depending on size
- Cold-drawn bar
- Tighter across-flats tolerance (for example to h11) on request
Machining, welding and corrosion protection
Machining
T6 bar of all four grades machines well; 6061 and 6082 give the cleanest chips. Use positive-rake carbide and coolant. Avoid O and T4 for heavy turning.
Threads
Cut or rolled threads both work in T6. Use anti-seize on stainless fasteners and avoid aluminium threads in high-cycle loading.
Welding
Weldable with ER5356 or ER4043, but the heat-affected zone loses roughly half its T6 strength. Hex fittings are usually machined, not welded.
Anodising
Clear anodising to 15 – 25 µm is the most effective protection in marine air; 6060 gives the most even appearance.
Galvanic isolation
Separate from stainless steel, bronze and carbon steel with insulating washers and sleeves; seal crevices.
Immersion
For constant seawater immersion, switch to 5083 or 5086, or protect with coatings and anodes.
Typical marine uses
- Hose and pipe fittings for fuel, fresh-water, hydraulic return and ventilation systems
- Union nuts and adaptors on deck equipment and davits
- Stand-offs and spacers for electrical panels, antennas and instruments
- Cable gland bodies and bulkhead connectors
- Deck hardware such as cleat bases, rail fittings and canopy hardware
Which grade should you order?
| Requirement | Recommended alloy |
|---|---|
| Decorative fittings, best anodised look | 6060-T6 |
| Moderate load, cost-sensitive | 6005A-T6 or 6060-T6 |
| Drawing to ASTM / JIS, machined parts | 6061-T6 or T6511 |
| Highest strength, European drawing | 6082-T6 |
| Permanent seawater immersion | A 5xxx alloy instead (5083, 5086) |
Ordering marine hex bar
- SpecifyAlloy, temper, across-flats size, length, quantity and standard (EN 755, ASTM B221 or GB/T 3191).
- QuoteAvailability, certificate and terms (EXW, FOB, CIF or DAP).
- PrepareCut, mark with alloy and cast, and inspect.
- ShipEN 10204 3.1 certificate; wooden cases or bundles for export.
References and standards
- EN 573-3 – Chemical composition and form of wrought products
- EN 755-2 – Extruded rod/bar, tube and profiles: mechanical properties
- EN 755-6 – Extruded hexagonal bar: tolerances on dimensions and form
- ASTM B221 – Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits
Marine 6xxx aluminium (aluminum) hex bar: FAQs
Which is stronger, 6082 or 6061 hex bar?
In T6, 6082 is slightly stronger: EN 755-2 minimums are 310 / 260 MPa for 6082 (20 – 150 mm) against 260 / 240 MPa for 6061.
Is 6060 hex bar suitable for marine use?
Yes for lightly loaded fittings above the waterline, especially when anodised. It is the weakest of the four grades, so check load-bearing parts.
What does T8511 mean?
Solution heat-treated, cold-worked, stress-relieved by stretching and artificially aged. It gives T6-class strength with reduced residual stress.
How much does a 24 mm aluminium hex bar weigh?
About 1.35 kg per metre in any 6xxx alloy.
Can 6xxx hex bar be used underwater?
It can with anodising or coating and galvanic isolation, but 5083 or 5086 is the safer choice for permanent seawater immersion.
Do you supply hex bar to ASTM standards?
Yes. 6061 hex bar can be certified to ASTM B221 (extruded) or B211 (cold finished); 6060, 6005A and 6082 are usually certified to EN 755.
Need marine hex bar?
Send alloy, temper, size, length, quantity and destination for availability, certification and a delivered price.
