| Internal Grade | SAE/AISI | IS | BS 970:1955 | BS 970:1983 | EN | JIS | DIN | GOST | ISO | AFNOR | GB/T | UNI | SS | CSA | AS/NZS |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| FC1213 | 1213 | 11C10S25 | EN1A | 220M07 | 11SMn30 | SUM22 | 9SMn28 | 15KhSND | 11SMn30 | XC10TS | Y15 | Fe360B | 1914 | G12130 | AS 1443 1213 |
| FC12L14 | 12L14 | — | EN1APb | 220M07Pb | 11SMnPb30 | SUM24L | 9SMnPb36 | 15KhSNDPb | 11SMnPb30 | XC10TS Pb | Y15Pb | Fe360PbB | 1914Pb | G12144 | AS 1443 12L14 |
| FC1137 | 1137 | 40Mn15S12 | EN15(AM) | 216M36 | ~36MnS4 | — | ~37Mn5S | — | ~38MnS4 | — | — | 37MnS4 | — | G11370 | AS 1443 1137 |
| SFC1146 | 1146 | 40C10S18 | EN8M | 212M36 | 44SMn28 | — | ~41Cr4S | 40Kh | 44SMn28 | XC45TS | Y40Mn | — | — | G11460 | AS 1443 1146 |
| FC1215 | 1215 | 11C14S20 | — | — | 9SMn36 | SUM23 | 9SMn36 | 15KhSN | 9SMn36 | XC14TS | Y12 | — | 1915 | G12150 | AS 1443 1215 |
Note: Some free cutting steels are specially optimized with lead (Pb) or sulphur (S) additions for machinability, and may not be chemically identical across standards. Grades like 12L14 and SUM24L contain lead. Ensure compatibility for heat treatment and weldability requirements.