Cast Iron Cross-Reference: Gray, Ductile & Malleable Iron
This international cast iron cross-reference compares grades across JIS, DIN, BS, AFNOR, UNI, UNE, SS, AISI/SAE and GB for gray, ductile and malleable iron—helping engineers and buyers select the right material across global supply chains, avoid property mismatches and improve CNC machining stability. For the material-group concept, see ISO Workpiece Material Classification.
Three Cast Iron Types
| Item | Description |
|---|---|
| Gray cast iron (FC) | flake graphite; best machinability, good damping, low cost. |
| Ductile / nodular iron (FCD) | nodular graphite; high strength and toughness, can replace some steels. |
| Malleable cast iron (FCM) | good ductility and impact resistance, for parts under deformation and vibration. |
Gray Iron (FC) Cross-Reference
| Japan JIS | Germany W-nr. | Germany DIN | UK BS | France AFNOR | Italy UNI | Spain UNE | Sweden SS | USA AISI/SAE | China GB |
|---|---|---|---|---|---|---|---|---|---|
| FC100 | – | GG10 | – | Ft10D | – | – | 0100 | No.20B | – |
| FC150 | 0.6015 | GG15 | Grade 150 | Ft15D | G15 | FG15 | 0115 | No.25B | HT150 |
| FC200 | 0.6020 | GG20 | Grade 220 | Ft20D | G20 | – | 0120 | No.30B | HT200 |
| FC250 | 0.6025 | GG25 | Grade 260 | Ft25D | G25 | FG25 | 0125 | No.35B | HT250 |
| FC300 | 0.6030 | GG30 | Grade 300 | Ft30D | G30 | FG30 | 0130 | No.45B | HT300 |
| FC350 | 0.6035 | GG35 | Grade 350 | Ft35D | G35 | FG35 | 0135 | No.50B | HT350 |
| – | 0.6040 | GG40 | Grade 400 | Ft40D | – | – | 0140 | No.55B | HT400 |
| – | 0.6660 | GGL NiCr202 | L-NiCuCr202 | L-NC202 | – | – | 0523 | A436 Type2 | – |
Ductile Iron (FCD) Cross-Reference
| Japan JIS | Germany W-nr. | Germany DIN | UK BS | France AFNOR | Italy UNI | Spain UNE | Sweden SS | USA AISI/SAE | China GB |
|---|---|---|---|---|---|---|---|---|---|
| FCD400 | 0.7040 | GGG40 | SNG 420/12 | FCS 400-12 | GS 370-17 | FGE 38-17 | 0717-02 | 60-40-18 | QT400-18 |
| – | – | GGG40.3 | SNG 370/17 | FGS 370-17 | – | – | 0717-12 | – | – |
| – | 0.7033 | GGG35.3 | – | – | – | – | 0717-15 | – | – |
| FCD500 | 0.7050 | GGG50 | SNG 500/7 | FGS 500-7 | GS 500 | FGE 50-7 | 0727-02 | 80-55-06 | QT500-7 |
| – | 0.7660 | GGG NiCr202 | Grade S6 | S-NC202 | – | – | 0776 | A436 D2 | – |
| – | – | GGG NiMn137 | L-NiMn137 | L-MN137 | – | – | 0772 | – | – |
| FCD600 | – | GGG60 | SNG 600/3 | FGS 600-3 | – | – | 0732-03 | – | QT600-3 |
| FCD700 | 0.7070 | GGG70 | SNG 700/2 | FGS 700-2 | GS 700-2 | FGE 70-2 | 0737-01 | 100-70-03 | QT700-2 |
Malleable Iron (FCM) Cross-Reference
| Japan JIS | Germany W-nr. | Germany DIN (GTS) | UK BS | France AFNOR | Italy UNI | Sweden SS | USA AISI/SAE |
|---|---|---|---|---|---|---|---|
| FCMB310 | – | – | B 290/6 | MN32-8 | – | 0814 | – |
| FCMW330 | – | GTS-35 | B 340/12 | MN35-10 | – | 0815 | 32510 |
| FCMW370 | 0.8145 | GTS-45 | P 440/7 | Mn450 | GMN45 | 0852 | 40010 |
| FCMP490 | 0.8155 | GTS-55 | P 510/4 | MP50-5 | GMN55 | 0854 | 50005 |
| FCMP540 | – | GTS-65 | P 570/3 | MP60-3 | – | 0858 | 70003 |
| FCMP590 | 0.8165 | GTS-65-02 | P 570/3 | Mn650-3 | GMN65 | 0856 | A220-70003 |
| FCMP690 | – | GTS-70-02 | P 690/2 | Mn700-2 | GMN70 | 0862 | A220-80002 |
※ These are approximate cross-references; chemistry and mechanical properties may differ. Verify against the original national standards (especially strength and elongation grades) before use.
Reading the Grade Codes
| Item | Description |
|---|---|
| Numbers indicate tensile strength | e.g. FC250 ≈ 250 MPa, FCD700 ≈ 700 MPa. |
| Ductile iron elongation | e.g. QT400-18 = 400 MPa tensile, 18% elongation. |
| Naming differs by country | JIS uses FC/FCD/FCM, DIN uses GG/GGG, GB uses HT/QT, AISI often numeric (e.g. 60-40-18). |
CNC Machining & Applications
| Item | Description |
|---|---|
| Gray iron | stable cutting, low distortion, good damping; for machine bases and castings. Use wear-resistant tools, often dry, mind graphite dust. |
| Ductile iron | near-steel strength; for gears and shafts. Higher cutting force than gray iron—balance wear resistance and toughness. |
| Malleable iron | high impact resistance; for auto parts and connectors. |
For cutting speeds, feeds and other parameters, see End Mill Cutting Conditions Guide.
FAQ
What are FC, FCD and FCM?
FC = gray iron (flake graphite, best machinability), FCD = ductile iron (nodular graphite, high strength & toughness), FCM = malleable iron (good ductility & impact). These are JIS codes.
What does the number in FC250 mean?
It is usually the minimum tensile strength—FC250 ≈ 250 MPa. For ductile iron, QT400-18 means 400 MPa tensile and 18% elongation.
Which JIS grade do DIN GG / GGG map to?
DIN GG (e.g. GG20) maps to JIS gray iron FC; DIN GGG (e.g. GGG40) maps to ductile iron FCD. See the tables above.
Which cast iron machines most easily?
Gray iron (FC) has the best machinability with stable cutting and good damping; ductile iron is stronger with higher cutting force; malleable iron resists impact. Use the cross-reference for selection and verify against national standards.
This article is part of Workpiece Materials: The Complete Guide - Name the Metal First, Then Match the Tool; that guide shows how the whole topic fits together.
