CI · cast iron
Ductile Iron GGG60 (EN-GJS-600-3)
A high-strength ductile iron: 600 MPa with 3% elongation. It machines like a medium carbon steel and it is unforgiving of a sharp internal corner, because almost all the ductility has been spent to get the strength.
Quoting this material
- Typical lead time
- 15–25 working days
- Condition
- As cast or normalised (pearlitic matrix)
- Achievable finish
- Ra 1.6 µm typical · Ra 0.8 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.
A high-strength ductile iron: 600 MPa with 3% elongation. It machines like a medium carbon steel and it is unforgiving of a sharp internal corner, because almost all the ductility has been spent to get the strength.
Properties as supplied
| Parameter | Value | Unit |
|---|---|---|
| Tensile strength | 600 | MPa |
| Yield strength (0.2%) | 370 | MPa |
| Elongation | 3 | % |
| Hardness | 190–270 | HB |
| Wear resistance | Better than lower grades | - |
| Modulus of elasticity | 170 | 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 cast or normalised (pearlitic matrix)
Heat treatment
Normalising is used to develop the pearlitic matrix that gives the strength. Where the application is a wear surface, a surface hardening treatment is applied after rough machining.
Achievable surface finish
Ra 1.6 µm
Ra 0.8 µm
Takes a good machined finish; ground surfaces are used where flatness or a seal is needed.
Tooling and cutting parameters
Cutting speed
- 100–220 m/min (carbide)
Feed
- 0.15–0.30 mm/rev turning · 0.08–0.18 mm/tooth milling
Tooling
- Coated carbide with a strong edge; ceramic for the cast skin
Coolant
- Flood or mist
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
- Gears and heavy-duty drive components
- Crankshafts and camshafts
- Wear liners and guide blocks
- Mining and quarry machinery parts
- Press and forming tooling bodies
DFM notes for this grade
- Only 3% elongation: a stress concentration that a GGG40 casting would shrug off will crack a GGG60 part
- The strength is in the pearlitic matrix, so machining is a little harder and tool life is shorter than on the lower ductile grades
- For a wear-critical part, compare against ADI before settling - ADI can double the strength at similar machinability
Questions buyers ask
- When should I use ADI instead of GGG60?
- When you need much higher strength or wear resistance. ADI is made from ductile iron by an austempering heat treatment and reaches 900–1,100 MPa with better wear resistance - at the cost of a heat treatment and much harder machining afterwards.
- Why is the elongation so low on the higher ductile grades?
- Because the matrix is being used for strength. The nodular graphite gives ductile iron its basic toughness, but as the matrix goes pearlitic and then bainitic the material gives up elongation for strength - 15% at 400 MPa, 3% at 600, 2% at 700.
Grades we would quote instead
GGG50 / Ductile Iron 500-7
5/10A higher-strength ductile iron with less elongation: harder matrix, longer tool life needed, and the cutting speeds step down accordingly.
GGG70 / Ductile Iron 700-2
5/10The top of the standard ductile iron range: 700 MPa with 2% elongation.
ADI (Austempered Ductile Iron)
3/10Ductile iron put through an austempering heat treatment to reach 800–1,100 MPa.