ISO K — Cast Iron · K30
K30 — Malleable iron
Hardness range: 150–230 HB. Part of the ISO K — Cast Iron group. Cast iron is abrasive and brittle — short chips, no built-up-edge. CVD alumina (Al₂O₃) coatings resist the high-temperature abrasion. Dry machining is acceptable for grey iron; coolant helps with nodular grades. Main failure mode: flank wear. High-speed machining is effective.
Material profile — K30
- ISO designation
- K30 (ISO K — Cast Iron)
- Material
- Malleable iron
- Hardness
- 150–230 HB
- ISO group colour
- Cast Iron
Tooling guidance — K-group
- Group summary
- CVD alumina coatings excel. Dry machining acceptable for grey CI. Abrasive wear is the main failure mode.
Insert selection for malleable iron — starting point
- ISO application class
- K (cast iron). Malleable iron sits between grey and ductile iron; it has some ductility, so a slightly tougher edge than a grey-iron grade helps. Match the ISO K class across brands rather than the brand name (Sandvik, Kennametal, Iscar, Walter, Seco and Mitsubishi each publish one), then confirm the exact grade for your condition.
- Grade & coating
- CVD-coated carbide, K10–K20. A little tougher than a pure grey-iron grade because malleable iron is more ductile.
- Geometry
- Negative geometry, honed edge for skin and interruptions. Mostly short chips.
- Starting parameters
- Vc ≈ 120–250 m/min, fn ≈ 0.10–0.40 mm/rev, dry or with coolant. Confirm in the advisor or on a sample part.
malleable iron: what goes wrong, and what to check first
- Abrasive flank wear
- Use a CVD-coated K-grade and a sensible speed.
- Mild built-up edge at low speed
- More ductile than grey iron, so it can build up at low speed. Raise the speed into the band.
- Edge chipping on cast skin
- Use a tougher grade with a honed edge and ease into the cut.
- Frittering at exit
- Reduce feed at exit or use a tougher grade.
Reference data
Insert grade index
ISO insert-code index
CNMG120408 — general turning
CCMT09T304 — positive finishing
Tool-wear diagnosis
Get cutting parameters for Malleable iron
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