SG iron 400/15 is a ferritic ductile (spheroidal graphite) cast iron with a minimum tensile strength of 400 MPa and 15% elongation. The round graphite nodules make it tough and ductile, unlike brittle grey iron. It is widely used for valve bodies, pump housings, pipe fittings and parts that must take shock.
Quick facts
- Type
- Ferritic spheroidal graphite (ductile) cast iron
- Tensile strength
- 400 MPa min
- Elongation
- 15% min
- Hardness
- About 130–180 HB
- Machinability
- Very good
- Compared with SG 500/7
- Softer and more ductile, lower strength
Equivalent grades
| Standard | Grade |
|---|---|
| EN | EN-GJS-400-15 (5.3106) |
| IS 1865 | SG 400/15 |
| ASTM A536 | Close to 60-40-18 |
| ISO 1083 | 400-15 |
Equivalents are close, not identical. Name the grade and standard on the drawing.
Typical properties
| Property | Value |
|---|---|
| Tensile strength | 400 MPa min |
| 0.2% proof stress | About 250 MPa min |
| Elongation | 15% min |
| Hardness | About 130–180 HB |
Values are typical. The exact limits depend on the standard and supplier; ask for the mill test certificate when it matters.
Typical uses
- Valve bodies and bonnets
- Pump housings and impellers
- Pipe fittings and couplings
- Brackets, levers and automotive parts
- Parts that must take shock without cracking
Need parts made in SG iron 400/15 (EN-GJS-400-15)?
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Questions
- What does 400/15 mean?
- 400 MPa minimum tensile strength and 15% minimum elongation, measured on separately cast test bars.
- SG 400/15 or SG 500/7?
- 400/15 is softer and more ductile, good for pressure parts and shock. 500/7 is stronger and harder, used where strength and wear matter more than ductility.
- Is SG iron weldable?
- It can be welded with nickel-based fillers and preheating, but it is tricky. Repairs on pressure parts should follow the customer's rules.
The figures on this page are typical values for guidance, written by Diemeco from standard engineering practice. They are not a specification: confirm grades and properties with the relevant standard or the supplier's mill test certificate, and tolerances with your workshop. Last checked 16 October 2026.