Quick Answer
Non-ferrous alloys are metal alloys that contain no significant iron. The major families are aluminum, copper (brass and bronze), nickel, magnesium, zinc and titanium alloys. Buyers pick them over steel or cast iron for three main reasons: lower weight, corrosion resistance without coatings, and electrical or thermal conductivity. The trade-off is usually cost per kilogram and, for some families, lower strength or temperature limits.
The Main Non-Ferrous Alloy Families
| Family | Typical density | Key strengths | Common cast parts |
|---|---|---|---|
| Aluminum alloys (A356, ADC12, 6061) | 2.7 g/cm³ | Light, corrosion resistant, cheap to cast | Housings, brackets, heat sinks, automotive parts |
| Copper alloys — brass, bronze | 8.4–8.9 g/cm³ | Conductivity, wear resistance, sea-water resistance | Bushings, impellers, valve trim, marine fittings |
| Nickel alloys (CN7M, Monel, Inconel types) | 8.4–8.9 g/cm³ | Acid and heat resistance | Chemical pump parts, furnace components |
| Magnesium alloys (AZ91) | 1.8 g/cm³ | Lightest structural metal | Electronics housings, aerospace brackets |
| Zinc alloys (Zamak) | 6.6 g/cm³ | Excellent for thin-wall die casting | Hardware, small housings, decorative parts |
| Titanium alloys (Ti-6Al-4V) | 4.4 g/cm³ | Strength-to-weight, biocompatibility | Aerospace and medical components |
Ferrous vs Non-Ferrous: The Practical Difference for Buyers
Ferrous materials (carbon steel, alloy steel, cast iron, stainless steel) dominate where raw strength per dollar matters. Non-ferrous alloys win when the application punishes iron-based metals:
- Weight-critical assemblies. Swapping a gray iron housing for A356 aluminum cuts mass by roughly 60% at similar wall thickness.
- Corrosive media without paint or plating. Bronze and nickel alloys survive sea water and acids where coated steel eventually fails at the coating.
- Electrical and thermal paths. Copper alloys conduct; steel does not, in any useful sense.
- Non-magnetic requirements. Instrumentation and some electronics enclosures cannot tolerate ferromagnetic materials.
Note that stainless steel is still ferrous — buyers sometimes lump it with non-ferrous metals because it resists rust, but its iron base puts it in a different family with different casting behavior. We compared the two directly in our guide to cast vs wrought aluminum for the aluminum side of that decision.
How Non-Ferrous Alloys Are Cast
Process choice depends mostly on melting point and volume:
- Aluminum: sand casting for low volume and large parts, gravity die casting and low-pressure casting for repeatable mid-volume production.
- Copper and nickel alloys: sand casting and investment casting; investment casting when the part needs fine detail or minimal machining.
- Zinc and magnesium: almost always high-pressure die casting, at high volumes.
Selection Checklist for Your RFQ
- Operating environment: media, temperature, chloride or acid exposure
- Weight budget: does the assembly actually need light metal, or is that habit?
- Conductivity or magnetic requirements, if any
- Volume and target piece price — this often decides the casting process, which constrains the alloy list
- Machining plan: some bronzes and aluminum grades machine far faster, which can offset higher material cost
FAQ
Is stainless steel a non-ferrous metal?
No. Stainless steel is iron-based, so it is ferrous. It resists corrosion because of chromium, not because it lacks iron.
Which non-ferrous alloy is cheapest for castings?
Aluminum, in most cases. Zinc can beat it at very high volumes in die casting because of faster cycle times and long die life.
Can one foundry cast both ferrous and non-ferrous parts?
Some can. YCUMETAL casts stainless and carbon steels alongside aluminum alloys, which lets buyers consolidate mixed-material assemblies with one supplier.