12L14
Data verified12L14 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.
Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤0.15 |
| Mn | 0.85–1.15 |
| P | 0.04–0.09 |
| S | 0.26–0.35 |
| Pb | 0.15–0.35 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Tensile strength | 390–470 MPa (hot rolled, typ.) |
| Machinability | ≈160–170% of 1212 (typ. rating) |
| Density | 7.85 g/cm³ |
Heat treatment
Used cold drawn as supplied; no heat treatment response at this carbon level.
Equivalent grades
| Standard | Designation |
|---|---|
| din | 11SMnPb30 family (near) |
| aisi | 12L14 |
| jis | SUM24L (near) |
| gb | Y12Pb (near) |
Compare side by side: 12L14 vs 1215 · 12L14 vs Y12
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Precision turned parts, hydraulic fittings, connectors, fasteners, instrument components.
Processing: Best-in-class chip breaking and tool life; cannot be welded reliably; check RoHS/lead restrictions for the destination market.
FAQ
- Why does 12L14 machine so fast?
- Lead acts as an internal lubricant and chip breaker at the cutting edge, and the high sulfur forms manganese sulfides. The result is the benchmark machinability rating against which other free-cutting steels are measured.
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Ask for a quotationVisit NasteelSource: SAE J403 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.