SAE 12L14 Free-Machining Steel
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Key Engineering Properties
Representative source rows, qualified by their reported conditions. Inspect the tables below for all values, limits, and source notes.
Engineering Summary
SAE 12L14 is a leaded resulfurized and rephosphorized free-machining carbon steel providing the benchmark 100% screw machine machinability rating and exceptional surface finish.
Recognized Aliases
Source-backed commercial trade name and short designations cataloged in canonical data.
SAE 12L14 Free-Machining Steel Specifications & Designations
Standard Designations & Applicable Specifications — Semantically classified designations distinguishing primary standard identifiers, commercial trade names, and applicable specification references.
| System | Identifier | Standard System Name | Classification Notes & Provenance |
|---|---|---|---|
| SAEPRIMARY | 12L14 | Society of Automotive Engineers | —Ref: Practical Data for Metallurgists, 19th edition |
| AISI | 12L14 | American Iron and Steel Institute | —Ref: Practical Data for Metallurgists, 19th edition |
| UNS | G12144 | Unified Numbering System | —Ref: Practical Data for Metallurgists, 19th edition |
| Standards Body | Specification Code | Specification Title / Scope | Relationship Type |
|---|---|---|---|
| SAE | SAE 12L14 Free-Machining Steel Engineering Datasheet | Applicable specification reference. | Specification Reference |
SAE 12L14 Free-Machining Steel Chemical Composition
Chemical Composition (Weight %) — Elemental limits and values from the cited source. Preserves exact semantic limits (minimums, maximums, and ranges).
| Element | Symbol | Atomic No. | Semantic Basis | Specified Value | Unit | Metallurgical Notes & Qualification | Data Status |
|---|---|---|---|---|---|---|---|
| Iron | Fe | 26 | BALANCE | Balance | wt% | Ref: Metallus | VERIFIED |
| Carbon | C | 6 | MAXIMUM | ≤ 0.15 | wt% | Ref: Metallus | VERIFIED |
| Manganese | Mn | 25 | RANGE | 0.85 – 1.15 | wt% | Ref: Metallus | VERIFIED |
| Phosphorus | P | 15 | MAXIMUM | ≤ 0.09 | wt% | Ref: Metallus | VERIFIED |
| Sulfur | S | 16 | RANGE | 0.26 – 0.35 | wt% | Ref: Metallus | VERIFIED |
| Lead | Pb | 82 | RANGE | 0.15 – 0.35 | wt% | Ref: Metallus | VERIFIED |
SAE 12L14 Free-Machining Steel Physical Properties
Source-specific physical properties. Test temperatures are shown only where reported.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Density | 7.87 g/cm³ | TYPICAL | 7.87 g/cm³ | Metallus | VERIFIED | |
| Elastic Modulus | 205 GPa | TYPICAL | 205 GPa | Metallus | VERIFIED | |
| Poisson's Ratio | 0.29 dimensionless | TYPICAL | 0.29 dimensionless | Metallus | VERIFIED |
SAE 12L14 Free-Machining Steel Thermal & Thermodynamic Properties
Phase change temperatures, thermal conductivity, specific heat, mean coefficients of thermal expansion across standardized temperature ranges, and recommended thermal processing windows.
| Property Parameter | Canonical SI Value | Semantic Basis | Test Temperature / Context Range | Source Raw Reference | Source Reference | Status |
|---|---|---|---|---|---|---|
| Specific Heat Capacity | 486 J/(kg·K) | TYPICAL | 486 J/(kg·K) | Metallus | VERIFIED | |
| Thermal Conductivity | 51.9 W/(m·K) | TYPICAL | 51.9 W/(m·K) | Metallus | VERIFIED |
SAE 12L14 Free-Machining Steel Mechanical Properties
Contextual Mechanical Properties & Tempers: Engineering strength, ductility, and hardness values grouped by product form, temper, and section thickness. Mechanical properties are contextual and not isotropic averages.
| Product Form | Temper / Condition | Section Size | Tensile (UTS) | Yield Strength | Elongation | Shear Strength | Fatigue Strength | Hardness (Scales Preserved) | Status |
|---|---|---|---|---|---|---|---|---|---|
| Bar | Cold Drawn Bar (19 to 32 mm)Source values and qualifiersUltimate Tensile Strength: ≥ 540 MPa (MINIMUM)ASTM A108 / ASTM E8Metallus — p118, Estimated Minimum Properties for Cold Drawn Bars Reduction of Area: ≥ 35 % (MINIMUM)ASTM A108 / ASTM E8Metallus — p118, Estimated Minimum Properties for Cold Drawn Bars | — | ≥ 540 MPa | — | — | — | — | — | VERIFIED |
| Bar | Cold Drawn Bar (19 to 32 mm)Source values and qualifiersYield Strength: ≥ 415 MPa (MINIMUM)ASTM A108 / ASTM E8 (0.2% offset)Metallus — p118, Estimated Minimum Properties for Cold Drawn Bars | — | — | ≥ 415 MPa | — | — | — | — | VERIFIED |
| Bar | Cold Drawn Bar (19 to 32 mm)Source values and qualifiersElongation at Break: ≥ 10 % (MINIMUM)ASTM A108 / ASTM E8Metallus — p118, Estimated Minimum Properties for Cold Drawn Bars | — · in 50 mm (2 in) | — | — | ≥ 10 % | — | — | — | VERIFIED |
| Bar | Cold Drawn Bar (19 to 32 mm)Source values and qualifiersHB Hardness: ≤ 197 HB (TYPICAL)Metallus — p118, Estimated Minimum Properties for Cold Drawn Bars | — | — | — | — | — | — | ≤ 197 HB | VERIFIED |
SAE 12L14 Free-Machining Steel Equivalent & Comparable Grades
Comparable Grades & Cross-References: Carefully classified cross-reference relationships for SAE 12L14 Free-Machining Steel. Comparable does not mean equivalent.
| Related Material | Family | Relationship Classification | Metallurgical Notes & Differences | Status | Action |
|---|---|---|---|---|---|
| SAE 1215 Carbon Steel | Steel | Commonly Compared | Lead-bearing free-machining carbon steel providing the fastest turning speeds and lowest tool wear in automated screw machines.Materials serve different design priorities (e.g. higher strength vs superior corrosion resistance or cost). | VERIFIED | Side-by-Side Compare → |
SAE/AISI Free-Cutting Steel Cluster (11xx & 12xx Series)
Resulfurized and rephosphorized engineering steels optimized for automated machining speeds, broken chip formation, and high surface finish.
Sources
Sources & Provenance Trail: Authoritative reference publications, standards specifications, and data registers cited across this material record.
Reviewed factual transcription from primary producer engineering technical literature.
Reviewed factual transcription from primary producer engineering technical literature.
Reviewed factual transcription from primary producer engineering technical literature.
Reviewed factual transcription from primary producer engineering technical literature.