Ductile iron casting (EN-GJS)
Ductile iron is a cast iron in which the graphite occurs as spheres; it is also known as spheroidal graphite or nodular cast iron. It is designated EN-GJS in the European standard EN 1563.
01 — Definition
Ductile iron: definition and graphite structure
In ductile iron, most of the carbon separates out as graphite in the form of spheres (nodules); the spherical shape reduces the stress concentrations created by flake graphite.
The grade name is written like EN-GJS-400-15: the first number gives the minimum tensile strength (MPa) and the second number the minimum elongation at fracture (per cent). The same grade is also referred to without the "EN-" prefix as GJS-400-15.
02 — Grades
EN 1563 grades and mechanical properties
- Standard values: awaiting metallurgical confirmation
| Grade | Older DIN (approx.) | Tensile strength Rm (MPa, min.) | Yield strength Rp0.2 (MPa, min.) | Elongation at fracture A (%, min.) |
|---|---|---|---|---|
| EN-GJS-400-15 | GGG40 | 400 | 250 | 15 |
| EN-GJS-500-7 | GGG50 | 500 | 320 | 7 |
| EN-GJS-600-3 | GGG60 | 600 | 370 | 3 |
| EN-GJS-700-2 | GGG70 | 700 | 420 | 2 |
The table scrolls horizontally on narrow screens
- The values in EN 1563 are for a separately cast test bar; the values in the part itself may differ according to wall thickness and process conditions.
- As strength increases, ductility decreases; this balance is the basis of grade selection.
- The GGG to EN-GJS correspondence is approximate, not exact.
- EN 1563 contains more grades; the table is limited to the four common grades.
03 — Matrix
Matrix structure
Even with the same spheroidal graphite structure, properties vary with the matrix: a ferritic matrix is more ductile, a pearlitic matrix is stronger and more wear-resistant.
How the matrix is adjusted is explained in the article.
04 — Selection criteria
Criteria for choosing a grade
The choice of grade and material depends on the part and its service condition; the following criteria offer a starting point for comparison.
- If resistance to permanent deformation under load and clear elongation are wanted.
- If impact or dynamic loading is involved.
- If the strength or ductility limit of grey iron is not enough.
- If vibration damping is not the primary requirement.
05 — SYC Demir Döküm
Ductile iron at SYC Demir Döküm
SYC Demir Döküm produces parts from grey and ductile cast iron. The pattern and mould work, simulation, core, casting, machining and coating stages are within the same company.
In the quality control department of SYC Demir Döküm, checks and tests are carried out on sand, metallurgy, metallography, precision dimensional measurement and coating quality.
| Topic | Value |
|---|---|
| EN-GJS grades produced at SYC | To be added (sample text) |
| Part weight range | To be added (sample text) |
| Heat treatment capability | To be added (sample text) |
| Type of material / test report provided | To be added (sample text) |
07 — FAQ
Frequently asked questions
What is ductile iron?
Ductile iron is a cast iron in which the graphite occurs as spheres; it is designated EN-GJS in EN 1563 and offers higher strength and elongation at fracture than grey iron.
What does EN-GJS-400-15 mean?
It shows that the grade is a spheroidal graphite cast iron with a minimum tensile strength of 400 MPa and an elongation at fracture of 15 %.
Which EN grade does GGG40 correspond to?
GGG40 corresponds approximately to the grade EN-GJS-400-15; the equivalence is not exact and should be confirmed before ordering.
Does SYC Demir Döküm produce ductile iron castings?
Yes. SYC Demir Döküm produces parts from grey and ductile cast iron. You can clarify which EN-GJS grade can be produced with our team by requesting a quote with your drawing and specification.
08 — Comparison
Compare with grey iron
If vibration damping and thermal conductivity stand out, you can also look at the grades on the grey iron (EN-GJL) page. A side-by-side comparison of the two materials is on the Materials page.
09 — Services
Related services
For the production stages and inspection of ductile iron:
Request a quote for your ductile iron part
You can start with a drawing or a short description.