Gray cast iron, or grey iron,flake graphite cast iron , is a type of cast iron that has a graphitic microstructure. It is named after the gray color of the fracture it forms, which is due to the presence of graphite. It is the most common cast iron and the most widely used cast material based on weight.
This is a comparison table for the gray iron grades of various standards including ISO, GB, ASTM, DIN, EN, JIS, UNI, NF, BS, IS, UNF, NBN, AS, SS, NS.
| Country | Standard | Equivalent Grades of Gray Iron (Grey Cast Iron) | ||||||
| ISO | ISO 185 | 100 | 150 | 200 | 250 | 300 | 350 | — |
| China | GB 9439 | HT100 | HT150 | HT200 | HT250 | HT300 | HT350 | — |
| Australia | AS 1830 | — | T150 | T220 | T260 | T300 | T350 | T400 |
| Belgium | NBN 830-01 | FGG10 | FGG15 | FGG20 | FGG25 | FGG30 | FGG35 | FGG40 |
| European | EN 1561 | EN-GJL-100 | EN-GJL-150 | EN-GJL-200 | EN-GJL-250 | EN-GJL-300 | EN-GJL-350 | |
| France | NF A32-101 | — | FGL150 | FGL200 | FGL250 | FGL300 | FGL350 | FGL400 |
|
Germany Austria |
DIN 1691 | GG10 | GG15 | GG20 | GG25 | GG30 | GG35 | GG40 |
| Japan | JIS G5501 | FC100 | FC150 | FC200 | FC250 | FC300 | FC350 | — |
| USA | ASTM A48 | — |
NO.20 NO.25 |
NO.30 | NO.35 |
NO.40 NO.45 |
NO.50 |
NO.55 NO.60 |
| Italy | UNI 5007 | G10 | G15 | G20 | G25 | G30 | G35 | — |
| UK | BS 1452 | 100 | 150 | 200 | 250 | 300 | 350 | — |
| India | IS 210 | — | FG150 | FG200 | FG260 | FG300 | FG350 | FG400 |
| Spain | UNF | — | FG15 | FG20 | FG25 | FG30 | FG35 | — |
| Sweden | SS 14 01 | O110 | O115 | O120 | O125 | O130 | O135 | O140 |
| Norway | NS11 100 | SJG100 | SJG150 | SJG200 | SJG250 | SJG300 | SJG350 | — |