Alloy series
3xxx Series — Aluminum–Manganese
The workhorse non-heat-treatable series. 20% stronger than 1xxx, still very formable.
Properties
3xxx — Traits and Typical Uses
| Common grades | 3003 · 3004 · 3005 · 3105 · 3A21 |
|---|---|
| Key traits | Good formability & weldability · Better strength than 1xxx · Excellent corrosion resistance · Non-heat-treatable |
| Typical uses | Roofing · Siding · Beverage can body · Heat exchanger · Cooking utensil |
| Heat treatable | No — strengthened by work hardening (H tempers) |
Every grade
All 5 Grades in the 3xxx Series
The series tells you the alloying element. The grade tells you how much of it, and that is what decides strength, corrosion behaviour and price. Grades with a detail page carry composition limits and temper-by-temper mechanicals.
| Grade | What it is for | Detail |
|---|---|---|
| 3003 | The general-purpose workhorse: forms, welds and resists weather without a coating. | Specs → |
| 3004 | Magnesium added for roughly a third more strength; can body and roofing coil. | Specs → |
| 3005 | Close to 3004 with tighter limits, used for architectural and appliance sheet. | On request |
| 3105 | Balanced manganese and magnesium for roofing and cladding coil, usually pre-painted. | Specs → |
| 3A21 | Chinese-registry Al-Mn grade close to 3003, seen on drawings from domestic OEMs. | On request |
A grade without a detail page is still quotable — the range, temper and certificate are confirmed on the offer rather than published as a table.
Specifying
How a 3xxx Order Is Written
Four things decide whether the material that arrives is the material you meant. None of them is the alloy number, which is usually the only thing on the enquiry.
1 — Temper, not just grade
The suffix sets the mechanical condition and changes strength more than the alloy does. This series is work hardened, so state the H temper and the degree: H12, H14, H18, or H32 where it is also stabilized. O means fully annealed and is a different material in behaviour.
2 — The product standard
ASTM, EN and GB do not have identical tolerance tables. Name the standard on the purchase order — 3xxx material supplied to a different edition can be perfectly good metal and still fail your incoming inspection.
3 — Thickness and its tolerance band
Nominal thickness is not the delivered thickness. State the band you can accept, especially near the sheet-plate boundary at 6.35 mm, where the product changes from cold-rolled sheet to hot-rolled plate.
4 — Certificate type
EN 10204 2.2 is a statement against general production; 3.1 carries the actual test values for your heat and is signed by an inspection representative independent of production. Say which one your file needs before the order is placed.
Choose
How 3xxx Compares
Choose 3xxx when
Roofing · Siding · Beverage can body · Heat exchanger · Cooking utensil
Think again if
You need heat-treated strength or a structural extrusion — go to 6xxx.
Other series
- 1xxx — Commercial Pure AluminumExcellent formability · Excellent corrosion resistance · High thermal/electrical conductivity · Non-heat-treatable
- 2xxx — Aluminum–CopperHigh strength after heat treatment · Good machinability · Poor corrosion resistance bare · Weldability varies
- 5xxx — Aluminum–MagnesiumExcellent marine corrosion resistance · Good weldability · Work-hardenable · Higher strength than 3xxx
- 6xxx — Aluminum–Magnesium–SiliconHeat-treatable (T5/T6) · Excellent extrudability · Good weldability · Excellent anodizing response
- 7xxx — Aluminum–ZincHighest strength · Heat-treatable · Lower corrosion resistance (stress corrosion risk) · Requires EN 10204 3.1
- 8xxx — Aluminum–Other (Foil & Special)High elongation · Low pinhole count · Clean surface · Non-heat-treatable
What goes wrong
Failure Modes That Show Up in 3xxx
These are the defects we get called about on this series, what causes them, and what to put on the order so they do not happen. Each page covers cause, measurement and specification.
- Pinholes in Aluminum FoilWhy aluminum foil gets pinholes: melt cleanliness, rolling oil filtration and thin gauge. How pinhole count is measured under ASTM B479 and GB/T 3198.
- Camber and Wavy Edge in Sheet & CoilWhy aluminum sheet and coil show camber or wavy edge, how it is measured under EN 485 and ASTM B209, and what to specify to keep it off your automatic line.
- Weld Cracking & Sensitization in 5xxx PlateWhy 5083 aluminum plate cracks or corrodes in service: Sensitization above 65°C, H116 vs H32 temper, filler wire choice, and the ASTM G67 test to specify.
- All eight failure modes →Symptom, cause, measurement, and the line to add to the order
Not Sure Between Two Grades?
Send the end use and the environment, and we will say which one we would run — including when the answer is "neither".
Ask for a Grade Recommendation