1.0718 | 11SMnPb30 +N (normalised)
| Numeric designation | 1.0718 |
|---|---|
| Chemical designation | 11SMnPb30 +N |
| State | +N (normalised) |
| Etching | 5% Nital |
Free-cutting steels are deliberately alloyed with sulphur (0.27-0.33%) and manganese (0.90-1.30%), as the long manganese sulphide (MnS) lines have a chip-breaking and lubricating effect when turning. The fine lead inclusions (0.2-0.35%) have the same effect and also ensure smooth surfaces. Recrystallised ferritic-pearlitic structure; the elongated MnS and pearlite lines still indicate the machining direction in the longitudinal section.
