12L14 vs Y12
These two grades are listed as equivalents of each other: their chemistry windows overlap and they serve the same applications. They are not always identical — check the differences below before substituting, especially in certified designs.
12L14
Carbon Steel
12L14 is the leaded free-cutting steel: lead, sulfur and phosphorus together give the highest machinability of any standard bar steel. It dominates high-volume turned parts where cycle time rules, at the cost of weldability and environmental restrictions on lead.
Standards: DIN 11SMnPb30 family (near) · AISI 12L14 · JIS SUM24L (near) · GB Y12Pb (near)
Y12
Carbon Steel
Y12 is China’s standard sulfur-phosphorus free-cutting steel (GB/T 8731), the domestic equivalent of the 1215 concept. It is produced in large volumes for automatic-lathe parts across Chinese machining shops.
Standards: AISI 1215 (near) · JIS SUM family (near) · GB Y12 (GB/T 8731)
Chemical composition compared (%)
| Element | 12L14 | Y12 |
|---|---|---|
| C | ≤0.15 | 0.08–0.16 |
| Mn | 0.85–1.15 | 0.70–1.00 |
| P | 0.04–0.09 | 0.08–0.15 |
| S | 0.26–0.35 | 0.23–0.33 |
| Pb | 0.15–0.35 | — |
| Si | — | ≤0.15 |
Properties compared
| Property | 12L14 | Y12 |
|---|---|---|
| Tensile strength | 390–470 MPa (hot rolled, typ.) | 380–460 MPa (hot rolled, typ.) |
| Machinability | ≈160–170% of 1212 (typ. rating) | — |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
Sourcing either grade?
Nasteel stocks both families from Shenzhen with EN 10204 3.1 mill certificates by heat number.
Ask for a quotationSee full data sheets: 12L14 · Y12. Substitution decisions for certified parts stay with the design authority.