The cross-reference is approximate
The cross-reference below is approximate. The standards use different test bars, units and minimum values. The standard named on your drawing always governs, and any substitution needs your written approval.
How to read the grade names
- EN-GJS-500-7 / QT500-7 / FCD500-7: minimum tensile strength 500 MPa, minimum elongation 7%.
- ASTM A536 80-55-06: minimum tensile strength 80 ksi, minimum yield strength 55 ksi, minimum elongation 6%.
- ГОСТ 7293 ВЧ50: minimum tensile strength 500 MPa (50 kgf/mm²). The number in a ВЧ grade is the tensile strength in MPa divided by 10.
- GGG-50: the former German DIN 1693 name, still common on older drawings. It was replaced by EN-GJS-500-7.
Ductile iron cross-reference chart
Scroll sideways to compare standards
| ASTM A536 (USA) | EN 1563 (Europe) | Old DIN | GB/T 1348 (China) | ГОСТ 7293 (Russia) | JIS G5502 (Japan) | Min. tensile | Min. 0.2% yield | Min. elongation |
|---|---|---|---|---|---|---|---|---|
| 60-40-18 | EN-GJS-400-18 EN-GJS-400-15 | GGG-40 | QT400-18 QT400-15 | ВЧ40 | FCD400-15 | 400 MPa (A536: 414 MPa) | 250 MPa (A536: 276 MPa) | 15–18% (A536: 18%) |
| 65-45-12 | EN-GJS-450-10 | — | QT450-10 | ВЧ45 | FCD450-10 | 450 MPa (A536: 448 MPa) | 310 MPa (FCD450-10: 280 MPa) | 10% (A536: 12%) |
| 80-55-06 | EN-GJS-500-7 | GGG-50 | QT500-7 | ВЧ50 | FCD500-7 | 500 MPa (A536: 552 MPa) | 320 MPa (A536: 379 MPa) | 7% (A536: 6%) |
| No direct match | EN-GJS-600-3 | GGG-60 | QT600-3 | ВЧ60 | FCD600-3 | 600 MPa | 370 MPa | 3% |
Values are the minimums in each standard for separately cast test samples. EN 1563, GB/T 1348 and JIS G5502 values are for the thinnest wall-thickness range (up to 30 mm); thicker sections have lower limits. ГОСТ 7293 lists elongation in an appendix that applies when it is specified. ASTM A536 has no direct match for 600-3; the nearest grades are 80-55-06 and 100-70-03.
Higher-strength grades (EN-GJS-700-2, QT700-2, ASTM A536 100-70-03 and above) exist in the standards. JK reviews them part by part against the drawing.
Gray iron vs ductile iron: graphite shape
Ductile iron and gray iron are both cast irons. The difference is the shape of the graphite: flakes in gray iron, round nodules in ductile iron. The nodules give ductile iron its elongation and impact strength.
Gray iron: flake graphite
Ductile iron: spheroidal (nodular) graphite
Which grade to choose
| If the part needs… | Usually start with | Why |
|---|---|---|
| Toughness, shock or low-temperature service, good machinability | EN-GJS-400-15 / QT400-15 / 60-40-18 | Mostly ferritic matrix, highest elongation |
| A balance of strength and ductility for housings, hubs and brackets | EN-GJS-450-10 / QT450-10 / 65-45-12 | Common general-engineering grade |
| Higher strength or wear resistance with moderate ductility | EN-GJS-500-7 / QT500-7 / 80-55-06 | Ferritic-pearlitic matrix |
| High strength and wear resistance where elongation is less critical | EN-GJS-600-3 / QT600-3 | Mostly pearlitic matrix, harder to machine |
These are starting points, not design rules. The final grade depends on loads, section thickness, service temperature and the inspection the drawing requires.
What to put on the drawing or RFQ
- The full designation and the standard, for example “EN-GJS-450-10 per EN 1563” or “ASTM A536 65-45-12”. “Ductile iron” on its own is not enough to quote against.
- Which properties must be verified: tensile test, elongation, hardness range, nodularity or microstructure. State whether results come from a separately cast bar or a cast-on bar.
- Heat treatment, if any (for example annealing to reach a ferritic matrix). Otherwise state “as-cast”.
- Inspection documents: for example an EN 10204 3.1 material certificate with chemical composition and mechanical test results.
- Whether equivalents are acceptable. If your drawing uses ASTM and you will accept the GB or EN grade, say so in writing.
How JK Casting supplies ductile iron
JK Casting makes custom ductile iron castings to customer drawings in Gaomi, Shandong, China. Regular ductile iron grades are QT400-15 to QT600-3 and their EN, ASTM and GGG equivalents. Ductile iron parts are normally produced by sand casting and can be supplied raw or CNC-machined to the drawing. The drawing’s standard governs, and material records such as EN 10204 3.1 certificates are provided when agreed for the order.
Related pages: Gray and ductile iron castings · Material selection · Sand casting vs investment casting · Send a drawing for quotation
Frequently asked questions
Is ASTM A536 65-45-12 the same as EN-GJS-450-10?
They are close but not identical. 65-45-12 requires 448 MPa tensile, 310 MPa yield and 12% elongation; EN-GJS-450-10 requires 450 MPa, 310 MPa and 10%. Many buyers treat them as equivalents, but the drawing’s standard governs and a substitution needs approval.
What is GGG-40 today?
GGG-40 is the former DIN 1693 designation. Its closest current European grade is EN-GJS-400-15, or EN-GJS-400-18 if higher elongation or impact performance is needed.
What is the Russian equivalent of QT500-7?
ГОСТ 7293 ВЧ50 has the same minimum tensile strength (500 MPa), 0.2% yield strength (320 MPa) and elongation (7%).
Is ductile iron the same as cast iron?
Ductile iron is a type of cast iron. Its graphite forms round nodules instead of the flakes in gray iron, which gives much higher elongation and impact strength.