Steel 12L14
EN 12L14 · UNS G12144 · JIS SUM24L · GB Y12Pb
12L14 is a leaded, resulfurized and rephosphorized low-carbon free-machining steel designed for high-volume turning of small parts on Swiss-type and cam-operated automatic lathes; machinability is among the highest of the carbon steels, roughly 160% with AISI 1212 rated 100%.
Values for the HR condition
12L14 tempers and conditions
12L14 is supplied in 4 conditions, soft to hard. HR is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HRDefault Hot rolled | Lowest-cost form for large sections or parts that will be fully machined; loose tolerances and scaled surface. | 230 | 395 | 22 | 121 HB | — |
subcritical / stress-relief anneal after cold drawing | Pick when cold-drawn stock must be softened or de-stressed to avoid distortion in long, slender or asymmetric machined parts. | 250 | 390 | 25 | 111 HB | — |
Cold rolled | Choose for flats, strip or TGP bar where a bright, dimensionally tight surface is needed without further sizing. | 400 | 515 | 12 | 150 HB | — |
Cold drawn | Default stock condition for round/hex/square bar: best size tolerance, straightness and surface for automatic turning. | 415 | 540 | 10 | 163 HB | — |
What is 12L14?
12L14 is a leaded, resulfurized and rephosphorized low-carbon free-machining steel designed for high-volume turning of small parts on Swiss-type and cam-operated automatic lathes; machinability is among the highest of the carbon steels, roughly 160% with AISI 1212 rated 100%. It is supplied mainly as cold-drawn round and hex bar with good dimensional accuracy and surface finish. Strength is moderate, toughness low, weldability and hot formability poor, and corrosion resistance is that of plain carbon steel, so plating or oiling is required. Lead content restricts use under RoHS/REACH in some markets and in food or drinking-water contact; specify a non-leaded resulfurized grade such as 1215 where that applies. 12L14 has a density of 7.87 g/cm³ (0.284 lb/in³), heavier than 92% of steel grades. It melts at 1,425°C (2,597 °F). 12L14 has a yield strength of 230 MPa (33.4 ksi) and a tensile strength of 395 MPa (57.3 ksi) — weaker than 97% of steel grades. Elongation at break is 22% and the elastic modulus is 200 GPa (29 Msi).
What is 12L14 used for?
- Machined fittings
- Fasteners
- Valve bodies
Advantages
- Easy to machine — 90/100, better than 99% of steel grades
- Conducts heat well — 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
Limitations
- Low strength — 230 MPa (33.4 ksi), worse than 97% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
12L14 properties
Typical room-temperature values for 12L14-HR; bars are the position among steel grades.
Physical3
12L14 has a density of 7.87 g/cm³ (0.284 lb/in³), heavier than 92% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical12
12L14 has a yield strength of 230 MPa (33.4 ksi) and a tensile strength of 395 MPa (57.3 ksi) — weaker than 97% of steel grades. Elongation at break is 22% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
12L14 is rated for continuous service to 300°C (572 °F). It conducts heat at 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
12L14 conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (9/100), worse than 98% of steel grades.
Sustainability4
Producing a kilogram of 12L14 takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 35%.
Manufacturability6
12L14's machinability is excellent (90/100, better than 99% of steel grades); weldability poor (15/100); formability fair (40/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. 12L14 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 12L14
Is 12L14 easy to machine?
Benchmark free-cutting steel: run high surface speeds with sharp positive-rake tooling and light feeds; the Pb/MnS produces short chips, excellent finish and long tool life — collect lead-bearing chips/mist properly.
Can 12L14 be welded?
Essentially not weldable — high S/P and Pb cause hot cracking and porosity; use mechanical fastening, brazing or press fits instead.
Can 12L14 be formed, bent or molded?
Limited cold formability: light knurling, thread rolling and shallow bends are practical, but tight bends and hot working risk hot-shortness from lead and sulfides.
Manufacturability
The process limits FabDigit's quote engine applies to 12L14. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Excellent90 / 100 |
|---|---|
| ISO material group | P.1 |
| Cutting speed (rough / finish) | 220 / 260 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
12L14 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cmax only | ≤ 0.15 | 0.1 |
| Mn | 0.85 – 1.15 | 1 |
| Prephosphorized for chip breaking | 0.04 – 0.09 | 0.06 |
| SMnS inclusions | 0.26 – 0.35 | 0.3 |
| Pbfree-machining lead addition | 0.15 – 0.35 | 0.25 |
| Fe | balance |
What surface finishes work on 12L14?
No corrosion resistance of its own — specify zinc, zinc-nickel or electroless nickel plating, black oxide, phosphate + oil; plating adhesion can suffer from lead smear, so degrease and activate thoroughly.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 12L14 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does 12L14 cost?
12L14 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
12L14 — frequently asked
What is 12L14 used for?
12L14 is typically used for machined fittings, fasteners and valve bodies. In short: super-fast machining; standard.
What is the yield strength of 12L14?
12L14 has a typical yield strength of 230 MPa (33.4 ksi) and a tensile strength of 395 MPa (57.3 ksi) — weaker than 97% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is 12L14 easy to machine?
Yes — machinability is rated excellent (90/100, better than 99% of steel grades). Benchmark free-cutting steel: run high surface speeds with sharp positive-rake tooling and light feeds; the Pb/MnS produces short chips, excellent finish and long tool life — collect lead-bearing chips/mist properly.
Can 12L14 be welded?
Not readily — weldability is rated poor (15/100). Essentially not weldable — high S/P and Pb cause hot cracking and porosity; use mechanical fastening, brazing or press fits instead.
What surface finishes work on 12L14?
No corrosion resistance of its own — specify zinc, zinc-nickel or electroless nickel plating, black oxide, phosphate + oil; plating adhesion can suffer from lead smear, so degrease and activate thoroughly.
Can 12L14 be formed, bent or molded?
Limited cold formability: light knurling, thread rolling and shallow bends are practical, but tight bends and hot working risk hot-shortness from lead and sulfides.
What is the maximum service temperature of 12L14?
12L14 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 12L14-HR and 12L14-CD?
HR is the default condition — lowest-cost form for large sections or parts that will be fully machined; loose tolerances and scaled surface. CD: default stock condition for round/hex/square bar: best size tolerance, straightness and surface for automatic turning. Yield strength is 230 MPa in HR versus 415 MPa in CD.
How much does 12L14 cost?
12L14 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in 12L14?
Yes — 12L14 is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A29/A29M — General Requirements for Steel Bars — ASTM (2020)
- ASTM A108 — Steel Bar, Carbon and Alloy, Cold-Finished — ASTM (2018)
- SAE J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
- GB/T 8731 — (Y15Pb equivalent) — SAC (2008)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.