Grey iron casting (EN-GJL)
In Turkey, "pik döküm" is the name used for flake graphite (grey) cast iron; the graphite occurs in flake form. It is designated EN-GJL in the European standard EN 1561. This name does not mean pig iron (the raw iron ingot).
01 — Definition
Grey iron: definition and graphite structure
In grey iron the graphite separates out in flake (lamella) form; because the tips of the flakes create stress concentrations, ductility is low, while vibration damping and thermal conductivity stand out.
The grade name is written like EN-GJL-250; the number gives the minimum tensile strength (MPa) measured on a separately cast test bar. The older DIN designation is GG25; the same grade is also referred to without the "EN-" prefix as GJL-250.
02 — Grades
EN 1561 grades and mechanical properties
- Standard values: awaiting metallurgical confirmation
| Grade | Older DIN (approx.) | Tensile strength Rm (MPa) | 0.1 % proof strength Rp0.1 (MPa) |
|---|---|---|---|
| EN-GJL-150 | GG15 | 150 - 250 | 98 - 165 |
| EN-GJL-200 | GG20 | 200 - 300 | 130 - 195 |
| EN-GJL-250 | GG25 | 250 - 350 | 165 - 228 |
| EN-GJL-300 | GG30 | 300 - 400 | 195 - 260 |
| EN-GJL-350 | GG35 | 350 - 450 | 228 - 285 |
The table scrolls horizontally on narrow screens
- The grade name is the lower limit of the tensile strength range; the upper limit is 100 MPa above the grade name.
- The values in the part deviate from the test bar according to wall thickness; strength falls in thick sections.
- The GG to EN-GJL correspondence is approximate.
03 — Selection
Selection criteria
Grey iron is considered when vibration damping, thermal conductivity, behaviour under compressive loading and cost stand out; ductile iron is suitable when high tensile strength, impact resistance and ductility are needed. Because section thickness affects the distribution of mechanical properties, the critical sections of the part are kept in mind when choosing the grade.
04 — SYC Demir Döküm
Grey 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.
| Topic | Value |
|---|---|
| EN-GJL grades produced at SYC | To be added (sample text) |
| Part weight range | To be added (sample text) |
| Type of material / test report provided | To be added (sample text) |
05 — Blog
Related articles
06 — FAQ
Frequently asked questions
What is grey iron?
In Turkey, "pik döküm" is the name used for flake graphite (grey) cast iron; it is designated EN-GJL in EN 1561 and stands out for vibration damping and thermal conductivity.
What does EN-GJL-250 mean?
It shows that the grade is a flake graphite cast iron with a tensile strength between 250 and 350 MPa on a separately cast test bar. Its older DIN equivalent is approximately GG25.
When are grey iron and ductile iron preferred?
Grey iron is considered when vibration damping, thermal conductivity and cost stand out; ductile iron when high strength, impact resistance and ductility are needed. The load type and service condition of the part decide.
Does SYC Demir Döküm produce grey iron castings?
Yes. SYC Demir Döküm produces parts from grey and ductile cast iron. You can clarify which EN-GJL grade can be produced with our team by requesting a quote with your drawing and specification.
07 — Comparison
Compare with ductile iron
If higher strength and elongation are needed, you can look at the grades on the ductile iron (EN-GJS) page. A side-by-side comparison of the two materials is on the Materials page.
08 — Services
Related services
For the production stages and inspection of grey iron:
Request a quote for your grey iron part
You can start with a drawing or a short description.