Wrought Magnesium Alloys
Wrought magnesium is the rolled, extruded and forged half of the family: Mg-Al-Zn alloys (AZ31B, AZ61A, AZ80A) that gain strength from aluminum and work hardening, Mg-Zn-Zr alloys (ZK60A) that are grain-refined by zirconium and aged, and the low-strength Mg-Mn grade M1A. At 1.77–1.83 g/cm³ they are the lightest structural stock a machine shop can buy — AZ31B-H24 sheet yields about 220 MPa and ZK60A-T5 extrusions about 300 MPa — and they cut faster than any other metal. The hexagonal crystal structure is the catch: sheet forms only warm, and strength is directional.
Popular wrought magnesium grades
Compare in the explorer| Grade | Yield, MPa | Tensile, MPa | Density, g/cm³ | Machinability | Weldability | Best for |
|---|---|---|---|---|---|---|
| AZ31B | 150 | 255 | 1.77 | Excellent | Very good | The default plate, sheet and extrusion; prototypes |
| AZ61A | 230 | 310 | 1.8 | Excellent | Very good | Stronger weldable extrusions |
| AZ80A | 250 | 340 | 1.8 | Excellent | Fair | Forgings and heavy extrusions, T5 aged |
| ZK60A | 260 | 340 | 1.83 | Excellent | Poor | Highest-strength forgings and wheels |
| M1A | 115 | 230 | 1.76 | Excellent | Excellent | Anodes, weldable low-strength parts |
| ZK61A | 195 | 310 | 1.83 | Excellent | Poor | High-zinc forging grade, T5 or T6 |
| HK31A | 200 | 255 | 1.79 | Excellent | Very good | Legacy 300 °C sheet on older aerospace drawings |
Choose wrought magnesium for
Machined prototypes and low-volume housings, optical and camera bodies, drone frames, laptop and instrument chassis, jigs and fixtures that an operator lifts all day, forged wheels and motorsport suspension, extruded rails and profiles, and any part where a 30 % weight saving over 6061 aluminum at similar stiffness is worth managing corrosion.
Look elsewhere when
The part sees water, salt or an uninsulated steel bolt (6061 or 5052 aluminum), it runs above about 120 °C under load (WE43 or 2618 aluminum), it must be bent cold from sheet (5052-H32 aluminum), the volume is high enough for a die casting (AZ91D at a fraction of the machining), or the design needs more than about 300 MPa yield or high fatigue life (7075-T6 aluminum or Grade 5 titanium).
Loading the library…
Wrought magnesium by application
- Machined prototypes and housings
- AZ31B plate (tooling plate is stress-relieved and flat) for form-fit-function prototypes of die castings and for low-volume enclosures; AZ80A or ZK60A bar when the machined part carries real load.
- Forged wheels and suspension
- ZK60A-T5 for racing wheels, uprights and bicycle cranks where fatigue governs; AZ80A-T5 as the more forgeable, more weldable alternative at about 10 % lower strength.
Working with wrought magnesium
- Machining
- The fastest-cutting structural metal: AZ31B runs at 2–3 × 6061 speeds with a fraction of the power, sharp tools and generous rake, dry or with mineral oil (never water-based coolant — it generates hydrogen). Chips must stay coarse and be cleared; fine dust is a fire risk and shops run magnesium on dedicated setups with Class D extinguishers. The high thermal expansion (26 µm/m·K) means letting parts reach room temperature before final measurement.
- Forming
- Hexagonal crystal structure limits room-temperature bending of AZ31B sheet to roughly 5–8 t (H24 worst, O-temper best); at 200–300 °C the same sheet bends to about 2 t, deep-draws and stretch-forms in heated tooling. Extrusions bend warm. Design bent parts to be formed hot or specify 5052 aluminum instead.
- Welding
- AZ31B, AZ61A and M1A TIG- and MIG-weld well with AZ61A or AZ92A filler under argon or helium; AZ80A welds with care and ZK60A is not fusion-welded (zinc causes hot cracking) — friction-stir welding covers it. Stress-relieve AZ alloys after welding (150–260 °C) to prevent stress-corrosion cracking, and expect the heat-affected zone to lose the H24 strain hardening.
- Heat treatment and finishing
- AZ31B is strain-hardened only (O, H24, H26); AZ80A, ZK60A and ZK61A are aged to T5 at 175–205 °C for 16–24 h, and ZK61A also takes a T6. Every wrought part needs a conversion coat — chromate (Dow 7), chrome-free phosphate-permanganate, or an anodic coating such as HAE, Dow 17 or Tagnite — followed by paint or powder for anything outdoors. Insulate steel fasteners with washers, sleeves or coated hardware.
Other magnesium alloy series
Wrought Magnesium Alloys — frequently asked
What is wrought magnesium?
Wrought magnesium is the rolled, extruded and forged half of the family: Mg-Al-Zn alloys (AZ31B, AZ61A, AZ80A) that gain strength from aluminum and work hardening, Mg-Zn-Zr alloys (ZK60A) that are grain-refined by zirconium and aged, and the low-strength Mg-Mn grade M1A. At 1.77–1.83 g/cm³ they are the lightest structural stock a machine shop can buy — AZ31B-H24 sheet yields about 220 MPa and ZK60A-T5 extrusions about 300 MPa — and they cut faster than any other metal. The hexagonal crystal structure is the catch: sheet forms only warm, and strength is directional.
Which grade of wrought magnesium should I use?
AZ31B for anything machined from plate or sheet, and for the prototype of a part that will later be die-cast in AZ91D: about 150–220 MPa yield depending on temper, every stock form, weldable and the easiest to source. AZ61A when an extrusion needs more than AZ31 (230 MPa yield as extruded) and still has to weld. AZ80A-T5 for forgings and heavy extrusions at about 275 MPa yield — wheels, brackets, suspension arms — and ZK60A-T5 when strength and fatigue matter most (about 300 MPa yield, 365 MPa tensile), accepting that it does not fusion-weld. M1A is the low-strength manganese grade for sacrificial anodes and parts that need the best weldability and salt-water corrosion behaviour of the group. ZK61A is ZK60A with more zinc for forgings; HK31A is the legacy thorium-bearing sheet for 300 °C service and appears only on old drawings.
Which grade of wrought magnesium is the strongest?
MB15 has the highest yield strength in the series at 275 MPa; ZK60A follows at 260 MPa. Values are for each grade's default condition.
Which grade of wrought magnesium is easiest to machine?
AZ31C (machinability excellent, 100/100), then AZ80A (98/100).
Is wrought magnesium heat-treatable?
Some grades are. Check the conditions listed on each grade page.
AZ31B or AZ80A for a machined part?
AZ31B for almost every prototype and housing: 150–220 MPa yield depending on temper, plate and sheet in every thickness, weldable, and enough for a part that was going to be die-cast anyway. AZ80A-T5 gives about 275 MPa yield and better fatigue for a bracket, wheel or suspension part that carries load, but it is a forging and heavy-extrusion alloy — bar and forged blanks rather than plate — and it welds poorly. If the part is machined from plate, the answer is AZ31B; if it is machined from a forging, AZ80A or ZK60A.
Can AZ31B replace 6061 aluminum in a plate part?
For a housing, chassis or fixture sized by stiffness or wall thickness, usually yes: AZ31B is 35 % lighter (1.77 against 2.70 g/cm³) and, because it is only 35 % less stiff (45 against 69 GPa), a plate of equal weight is stiffer in bending. Where it does not replace 6061 is strength (150–220 MPa yield against 275 for 6061-T6), threads and press fits under sustained load above about 100 °C, and any environment with water or dissimilar metals — the conversion coating and insulated fasteners are not optional the way they are on aluminum.