Aluminium Castings
Aluminium castings combine light weight, good corrosion resistance and excellent castability, made by sand, gravity die, pressure die or investment casting. They are used for housings, covers, brackets, impellers and heat sinks across automotive, electrical and machinery sectors.
What it is
Common alloys include LM6 (excellent castability and corrosion resistance), LM25 (heat-treatable, good strength), LM24/ADC12 (pressure die casting) and A356. The casting method is chosen by volume, size, wall thickness and properties needed.
Aluminium castings machine easily and can be anodised (low-silicon alloys), powder coated or impregnated for pressure tightness.
Typical applications
- Motor, pump and gearbox housings
- Automotive and two-wheeler parts
- Electrical enclosures and heat sinks
- Impellers and fans
- Brackets and machine covers
Suitable materials
- LM6 / A413
- LM25 / A356 (heat treatable)
- LM24 / ADC12 (pressure die)
- LM4 and other alloys
Points to consider
- High-silicon alloys anodise poorly; choose alloy by finish required.
- Pressure-tight parts may need vacuum impregnation.
- Choose LM25-TF where strength after heat treatment matters.
- Design walls and ribs for the chosen casting process.
Frequently asked questions
Which aluminium alloy is best for casting?
LM6 for complex shapes and corrosion resistance, LM25 where heat-treated strength is needed, and ADC12/LM24 for pressure die casting.
Can aluminium castings be anodised?
Yes, but high-silicon alloys give a grey, uneven finish. Low-silicon alloys anodise better.
How do you make aluminium castings pressure tight?
Sound casting practice plus vacuum impregnation seals any microporosity for hydraulic and pneumatic parts.