Gray Iron Casting is the most cost effective, popular used material in all over the world.

Gray iron grades are primarily categorized by their minimum tensile strength. Below are the comprehensive lists for the three requested standards.

1. Gray Iron Casting ASTM A48 (USA Standard)

The ASTM A48 / A48M standard uses “Class” numbers that represent the minimum tensile strength in thousands of pounds per square inch (ksi).

Class 20: 20 ksi (138 MPa)
Class 25: 25 ksi (172 MPa)
Class 30: 30 ksi (207 MPa)
Class 35: 35 ksi (241 MPa)
Class 40: 40 ksi (276 MPa)
Class 45: 45 ksi (310 MPa)
Class 50: 50 ksi (345 MPa)
Class 55: 55 ksi (379 MPa)
Class 60: 60 ksi (414 MPa)
Note: Each class can further include a suffix (A, B, C, or S) based on the test bar size, such as Class 30B.

2. EN 1561 (European Standard) Gray Iron Casting
The EN 1561 standard designates grades using the EN-GJL prefix, followed by the minimum tensile strength in MPa (N/mm²).
EN-GJL-100 (Material number: 5.1100)
EN-GJL-150 (Material number: 5.1200)
EN-GJL-200 (Material number: 5.1300)
EN-GJL-250 (Material number: 5.1400)
EN-GJL-300 (Material number: 5.1500)
EN-GJL-350 (Material number: 5.1600)

3. DIN 1691 (Old German Standard) Gray Iron Casting
Although DIN 1691 has been largely superseded by EN 1561, it remains widely referenced in technical drawings. It uses the GG prefix.
GG-10 (Material number: 0.6010)
GG-15 (Material number: 0.6015)
GG-20 (Material number: 0.6020)
GG-25 (Material number: 0.6025)
GG-30 (Material number: 0.6030)
GG-35 (Material number: 0.6035)
GG-40 (Material number: 0.6040)

Quick Comparison Table (Approximate Equivalence)
ASTM A48 EN 1561 DIN 1691
Class 20 EN-GJL-100 / 150 GG-10 / GG-15
Class 30 EN-GJL-200 GG-20
Class 35 EN-GJL-250 GG-25
Class 45 EN-GJL-300 GG-30
Class 50 EN-GJL-350 GG-35