O
Fully annealed. Maximum ductility for bending, heading, spinning and flaring. Lowest strength.
Formable, weldable aluminium-manganese bar
3003 Cold Finished Aluminium Bar and Rod
3003 is an aluminium-manganese alloy that is strengthened only by cold work, not heat treatment. As bar and rod it offers about 20 % more strength than 1100 with the same easy forming, welding and brazing and very good corrosion resistance. Metline supplies 3003 round, square, hex and flat bar in annealed and strain-hardened tempers to ASTM B211, ASTM B221 and EN 754 / 755, shipped worldwide.
- Alloy
- 3003 (Al-Mn-Cu), non-heat-treatable
- Tempers
- O, H12, H14, H16, H18, H112
- Strength
- About 110 – 200 MPa tensile by temper
- Standards
- ASTM B211 · B221 · EN 754 · EN 755
What is 3003 aluminium bar?
3003 is the most widely used aluminium-manganese alloy. About 1.2 % manganese, plus a small copper addition, raises its strength above commercially pure aluminium while keeping almost all of its ductility, corrosion resistance and weldability.
Because 3003 cannot be precipitation hardened, the strength of a bar depends entirely on how much cold work it received during drawing. Annealed (O) bar is soft and bends easily; half-hard H14 and full-hard H18 bar are stronger but less ductile. Choosing the right temper is therefore the main decision when buying 3003 rod.
Cold-finished bar is drawn through dies after extrusion, giving tighter diameter tolerances, a smoother surface and higher strength than as-extruded H112 bar. Typical uses include rivets and cold-headed parts, spun and formed components, heat-exchanger and HVAC fittings, brazed assemblies, chemical and food equipment parts, and electrical or decorative items where a soft, corrosion-resistant metal is wanted.
3003 chemical composition (wt %)
Limits per the Aluminum Association registration and EN 573-3 (EN AW-3003, AlMn1Cu). Composition is verified for every cast and reported on the mill test certificate.
| Element | Limit (%) | Role |
|---|---|---|
| Silicon (Si) | 0.6 max | Impurity |
| Iron (Fe) | 0.7 max | Impurity; combines with Mn in dispersoids |
| Copper (Cu) | 0.05 – 0.20 | Small strength gain; makes corrosion more uniform |
| Manganese (Mn) | 1.0 – 1.5 | Main alloying element; solid-solution and dispersoid strengthening |
| Zinc (Zn) | 0.10 max | Impurity |
| Others, each / total | 0.05 / 0.15 | |
| Aluminium (Al) | Remainder |
3A21 is a closely related alloy with a similar manganese range but no copper requirement. It is often accepted in place of 3003 for non-critical parts, but they are separate designations.
3003 mechanical properties by temper
Typical values from Aluminum Association / ASM data. Specified minimums for bar and rod are given in ASTM B211 (cold finished) and ASTM B221 (extruded) and are lower; design to those and to the certificate.
| Temper | Tensile strength (typical) | Yield strength (typical) | Elongation (typical) | Hardness |
|---|---|---|---|---|
| O (annealed) | 110 MPa / 16 ksi | 42 MPa / 6 ksi | 30 – 40 % | 28 HB |
| H12 (quarter hard) | 130 MPa / 19 ksi | 125 MPa / 18 ksi | 10 – 20 % | 35 HB |
| H14 (half hard) | 150 MPa / 22 ksi | 145 MPa / 21 ksi | 8 – 16 % | 40 HB |
| H16 (three-quarter hard) | 175 MPa / 26 ksi | 170 MPa / 25 ksi | 5 – 14 % | 47 HB |
| H18 (full hard) | 200 MPa / 29 ksi | 185 MPa / 27 ksi | 4 – 10 % | 55 HB |
| H112 (as extruded) | Close to O–H12; set by section | — | — | — |
Elongation is shown as a range because thin sheet specimens give the lower figure and 12.5 mm round specimens the higher. On bar, the higher value is the closer guide.
Physical properties (typical)
- Density
- 2.73 g/cm³ (0.099 lb/in³)
- Melting range
- about 643 – 654 °C
- Modulus of elasticity
- about 69 GPa (10,000 ksi)
- Thermal conductivity
- about 193 W/m·K (O); about 155 – 165 W/m·K (H tempers)
- Electrical conductivity
- about 50 % IACS (O); about 40 – 42 % IACS (H tempers)
- Coefficient of thermal expansion
- about 23.2 µm/m·°C (20 – 100 °C)
3003 tempers explained
H12 / H14
Quarter- and half-hard by cold drawing. H14 is the most common cold-finished bar temper: a balance of strength and formability.
H16 / H18
Three-quarter and full hard. Highest strength and the best machining finish, but limited bending.
H112
As extruded with a small amount of incidental work. Economical for larger sections where tight tolerances are not needed.
F
As fabricated, no property guarantees. Used as feedstock for further working.
Restoring ductility
Hard tempers can be annealed back to O at roughly 345 – 415 °C. Strength cannot be regained by heat treatment, only by more cold work.
3003 standards and international equivalents
| System | Designation | Bar and rod standards |
|---|---|---|
| Aluminum Association / ASTM | 3003 | ASTM B211 (cold finished), ASTM B221 (extruded) |
| UNS | A93003 | — |
| European (EN) | EN AW-3003 / AlMn1Cu | EN 573-3, EN 754-2 / 754-3 (drawn), EN 755-2 / 755-3 (extruded) |
| ISO | AlMn1Cu | ISO 209 |
| Japan (JIS) | A3003 | JIS H4040 |
| India (IS) | 31000 (similar Al-Mn grade) | IS 733 |
| GB | 3003 (3A21 related) | GB/T 3190, GB/T 3191 |
Many lots can be dual-certified to ASTM and EN. State on your order which standard governs tolerances and properties, because limits differ between them.
3003 bar forms, sizes and weights
| Form | Typical range | Tempers | Notes |
|---|---|---|---|
| Cold-finished round rod | About 3 – 75 mm diameter | O, H12, H14, H16, H18 | Tight tolerance, smooth finish |
| Extruded round bar | About 10 – 250 mm diameter | H112, O | Larger diameters, economical |
| Square and hex bar | About 6 – 75 mm | H14, H112 | Fittings and machined parts |
| Flat bar | Extruded or drawn sections | H112, H14 | Brackets, bus connections |
| Coiled rod / wire | Smaller diameters | O, H14, H18 | Rivets and cold heading |
Weights for solid round 3003 bar at 2.73 g/cm³:
| Diameter (mm) | kg per metre | 3 m bar (kg) | 6 m bar (kg) |
|---|---|---|---|
| 6 | 0.077 | 0.23 | 0.46 |
| 10 | 0.214 | 0.64 | 1.29 |
| 12 | 0.309 | 0.93 | 1.85 |
| 16 | 0.549 | 1.65 | 3.29 |
| 20 | 0.858 | 2.57 | 5.15 |
| 25 | 1.34 | 4.02 | 8.04 |
| 30 | 1.93 | 5.79 | 11.58 |
| 40 | 3.43 | 10.29 | 20.58 |
| 50 | 5.36 | 16.08 | 32.16 |
| 60 | 7.72 | 23.16 | 46.31 |
| 80 | 13.72 | 41.17 | 82.33 |
| 100 | 21.44 | 64.32 | 128.65 |
| 120 | 30.88 | 92.63 | 185.25 |
| 150 | 48.24 | 144.73 | 289.46 |
Forming, welding, brazing and machining
Forming and heading
Excellent cold formability in O and H12. Bend radii can be tight; full-hard H18 needs larger radii or annealing first.
Welding
Readily welded by TIG, MIG and resistance methods. 1100 or 4043 filler is common; the weld zone softens to near-O properties.
Brazing and soldering
One of the most brazeable alloys and a standard core alloy for brazed heat-exchanger components.
Machining
Soft and gummy in O; machine in H14 – H18 with sharp, polished, high-rake tools, high speeds and plenty of coolant to avoid built-up edge.
Anodising
Takes a protective anodic film well; the manganese gives a slightly grey tone, so 6063 or 5005 are preferred for bright decorative finishes.
Corrosion
Very good in air, fresh water and many chemicals. Use 5052 or 5083 where sea-water exposure is constant.
Tolerances and inspection
Cold-finished 3003 rod is held to the tighter diameter and straightness tolerances of ASTM B211 or EN 754-3; extruded bar follows ASTM B221 or EN 755-3. Ask for a specific tolerance class (for example h9 or h11) if your part relies on it.
- Chemical analysis for every cast
- Tensile testing to confirm temper, with results on the EN 10204 3.1 certificate
- Diameter, ovality, straightness and length checks
- Surface inspection for scratches, die lines and inclusions
- Lot traceability marked on each bundle
3003 compared with 1100, 5052 and 6061
| Property | 1100-H14 | 3003-H14 | 5052-H32 | 6061-T6 |
|---|---|---|---|---|
| Typical tensile strength | 125 MPa | 150 MPa | 230 MPa | 310 MPa |
| Formability | Excellent | Excellent | Good | Fair |
| Weldability / brazeability | Excellent / excellent | Excellent / excellent | Excellent / poor | Good / limited |
| Sea-water corrosion | Good | Good | Excellent | Good |
| Heat treatable | No | No | No | Yes |
Pick 3003 when you need a little more strength than 1100 and still want brazing. Choose 5052 for marine exposure or higher strength without heat treatment, and 6061 for structural machined parts.
Where 3003 bar and rod are used
- HVAC and heat transfer: fittings, headers and brazed components
- Fasteners: rivets and cold-headed parts that must stay ductile
- Chemical and food: equipment parts, handles and fittings in contact with food or mild chemicals
- Electrical: connectors, spacers and low-load conductors
- Architecture and decoration: rails, trims and turned decorative pieces
- General engineering: spun parts, pins and lightly loaded machined parts
How to order 3003 bar from Metline
- SpecifyAlloy 3003, temper (O, H12, H14, H16, H18 or H112), shape and size, length and quantity.
- Confirm the standardASTM B211 for cold-finished rod or ASTM B221 / EN 755 for extruded bar, plus any tolerance class or surface requirement.
- QuoteWe confirm availability, tolerance class, certification and delivery terms (EXW, FOB, CIF or DAP) for your destination port or site.
- Process and inspectBar is cut to length, checked for size, straightness and surface, and packed with interleaving to protect the finish.
- Document and shipEach lot ships with an EN 10204 3.1 mill test certificate and packing list. Bars are bundled or cased in seaworthy wooden boxes with moisture protection; third-party inspection can be arranged on request.
References and standards
- ASTM B211 / B211M – Aluminum and Aluminum-Alloy Rolled or Cold-Finished Bar, Rod, and Wire
- ASTM B221 / B221M – Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
- EN 573-3 – Chemical composition and form of wrought products (EN AW-3003)
- EN 754-2 – Cold drawn rod/bar and tube: mechanical properties
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
3003 aluminium (aluminum) bar: frequently asked questions
Can 3003 aluminium be heat treated to increase strength?
No. 3003 is non-heat-treatable; strength comes only from cold work. Heating will anneal it and reduce strength.
Which temper of 3003 rod should I order?
Order O for heavy bending or heading, H14 for a general balance of strength and formability, and H18 for the highest strength and best machined finish.
Is 3003 stronger than 1100?
Yes, by roughly 20 % in the same temper, thanks to its manganese content, with similar formability and corrosion resistance.
Is 3003 good for marine use?
It performs well in marine atmospheres, but for constant sea-water immersion 5052 or 5083 are better choices.
Can 3003 bar be welded and brazed?
Yes. It welds easily by TIG and MIG and is one of the most brazeable aluminium alloys.
What does a 25 mm 3003 round bar weigh?
About 1.34 kg per metre at a density of 2.73 g/cm³.
Need 3003 bar or rod?
Send form, size, temper, length and quantity. Our team will confirm availability, certification and delivered terms.
