MG · magnesium
Magnesium Alloy AM60B (die casting, ductile)
The ductile die-casting magnesium: less aluminium than AZ91, so lower strength but far better elongation. It machines easily and takes an excellent finish.
Quoting this material
- Typical lead time
- 12–20 working days
- Condition
- As die cast
- Achievable finish
- Ra 1.6 µm typical · Ra 0.4 µm best
Machined in-house to your drawing: see the precision CNC machining service and the machine and inspection capability it runs on.
Machinability
Our own 1–10 shop ranking, not a published index: 10 is free-cutting brass C360, 1 is Inconel 718. It ranks how a material behaves on the floor - cycle time, chip control and tool life together. Where a published index exists it is quoted in the note.
The ductile die-casting magnesium: less aluminium than AZ91, so lower strength but far better elongation. It machines easily and takes an excellent finish.
Properties as supplied
| Parameter | Value | Unit |
|---|---|---|
| Tensile strength | 220–240 | MPa |
| Yield strength (0.2%) | 130 | MPa |
| Elongation | 6–8 | % |
| Hardness | 60–65 | HB |
| Thermal conductivity | 62 | W/m·K |
| Modulus of elasticity | 45 | GPa |
Hardness, tensile and thermal figures are typical published values for the condition stated. Actual mill certificates govern; send the specification with the drawing and we confirm against the certificate before the material is cut.
Condition
As die cast
Heat treatment
Not hardenable by heat treatment. The B designation is the high-purity condition with controlled iron, nickel and copper for corrosion resistance.
Achievable surface finish
Ra 1.6 µm
Ra 0.4 µm
Excellent machined finish; the high-purity composition keeps the surface bright and the corrosion resistance usable with a conversion coating.
Tooling and cutting parameters
Cutting speed
- 300–700 m/min (sharp uncoated carbide)
Feed
- 0.10–0.35 mm/rev turning · 0.10–0.30 mm/tooth milling
Tooling
- Sharp uncoated carbide with large clearance
Coolant
- Mineral-oil mist or dry
Starting points for carbide on a rigid setup, not a guarantee. The right numbers depend on the machine, the toolholder and the fixturing - ask and we will say what we would actually run.
Typical applications
- Automotive seat frames and brackets
- Airbag housings and instrument panels
- Consumer electronics chassis
- Impact-resistant housings
- Steering wheel armatures
DFM notes for this grade
- The elongation is why it is specified: a seat frame or an airbag housing has to absorb impact without cracking, which AZ91D with 3% elongation cannot do
- Lower strength than AZ91: the section has to be sized for it, and the stiffness limit of magnesium applies to both grades
- Castability is slightly worse than AZ91, so a very thin-walled casting may still need the higher-aluminium grade at a cost in ductility
Questions buyers ask
- AM60B or AZ91D for an automotive casting?
- AM60B where the part has to absorb impact - seat frames, airbag housings, steering armatures - because the elongation is roughly double. AZ91D where the part is stiff and lightly loaded and the higher strength allows a thinner wall.
- Does the ductility make AM60 easier to machine?
- Marginally, and it makes it less prone to chipping at an edge. Both are easy to machine by metal standards; the difference is smaller than the difference in the casting design.
Grades we would quote instead
AZ91D
8/10The most common die-casting magnesium: high aluminium content gives good castability and decent strength, and it machines fast with excellent finishes.
AM50A
8/10The most ductile of the common die-casting magnesium grades: lower strength than AM60, higher elongation, and it machines like the rest of the family.
AZ91E
8/10The sand-casting version of AZ91 with a high-purity specification: lower strength than the die-cast grade but a far lower casting cost for low volumes, and it machines the same way.