Aluminium is the one common material where tool wear is usually not the limiting factor. Speeds are so high and the material so soft that a carbide edge can last a long time — the failures come from build-up edge, chip packing, and poor surface finish instead.
Real cutting data for ISO N
Aggregated from 210 insert records published for non-ferrous work in our catalogue:
| Parameter | Full published range | Typical (median) |
|---|---|---|
| Cutting speed vc | 300 – 600 m/min | 300 – 600 m/min |
| Feed fn | 0.03 – 0.40 mm/rev | 0.10 – 0.20 mm/rev |
| Depth of cut ap | 0.20 – 3.50 mm | 0.3 – 3.0 mm |
Many shops run faster than 600 m/min on wrought aluminium with polished inserts; above roughly 1000 m/min you are usually limited by the spindle, not the tool.
Grades that work
Our most-stocked non-ferrous grades: PD20, HS6120, HS7125, HS7225, HS8115, HS8125, AW100K.
The typical aluminium grade is an uncoated or lightly coated, fine-grain, polished carbide. Polishing matters: a smooth rake face gives the chip somewhere to slide instead of welding on. Do not use a general-purpose steel grade on aluminium — the TiN/TiCN coating has a high affinity with aluminium and will build up quickly.
The three real problems
1. Built-up edge (BUE)
Aluminium welds to a rough or worn carbide edge, and the welded lump then tears away, taking carbide with it. The result is a torn surface and rapid edge degradation. Fixes: polished grade, higher speed, sharp positive rake, and plenty of lubrication.
2. Chip evacuation
Aluminium chips are long and bulky unless the geometry breaks them, and in milling or deep holes they pack and re-cut. Fixes: sharp chipbreaker, high-pressure coolant or air blast, climb milling, and fewer teeth in the cutter.
3. Burr formation
Ductile aluminium forms large exit burrs. Fixes: sharp edge (a worn edge makes it far worse), positive rake, higher speed, and avoid a zero-feed dwell at the end of the cut.
Silicon content changes the whole picture
| Material | Character | Tooling |
|---|---|---|
| Wrought, low Si | Gummy, long chips | Sharp polished carbide, high rake |
| Cast Al, 7–12% Si (e.g. A356, ADC12) | Abrasive | Fine-grain carbide, lower speed; consider diamond-like coating |
| High-silicon Al (>12%), metal matrix composites | Very abrasive | PCD — carbide life will be uneconomical |
If you are machining high-silicon cast aluminium in volume and changing inserts every few parts, the answer is PCD, not a better carbide grade. Carbide simply cannot survive the silicon particles.
Geometry
- Positive rake always. Negative geometry in aluminium raises force, heat and BUE risk for no benefit.
- Large nose radius helps finish and heat, but watch the burr and the thin walls.
- Sharp, honed-minimal edge — aluminium wants the sharpest edge that will survive.
- Polished rake face is the single biggest improvement available.
Coolant
For milling, flood or high-pressure coolant mainly to clear chips and control heat in the part. For turning, a good emulsion works well. In many high-volume aluminium operations, MQL (minimum quantity lubrication) is the best compromise — enough lubrication to stop BUE without flooding the machine. Dry is possible with polished grades and sharp geometry, but BUE risk rises.
Where to start
- Turning: positive CCGT / DCGT style inserts, polished grade, vc 400–800, fn 0.10–0.25, ap 0.5–3
- Face milling: sharp positive milling geometry, few teeth, high fz, climb milling
- High-silicon castings: ask us about PCD
Related
- ISO 513 material groups explained
- Carbide grades explained
- Milling insert selection guide
- Browse milling inserts
Standards and further reading
The material group definitions used throughout this site follow ISO 513. The manufacturer links below are independent technical references.