Stainless Steel 347LN Cold Drawn
Supply condition
AISI/SAE 347LN · UNS S34751
Bar and tube where tighter tolerance, better surface and higher yield strength are needed than annealed.
Values for the Cold Drawn condition
Other 347LN tempers and conditions
347LN is listed in 8 conditions; see the grade overview at 347LN.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault solution annealed 1040–1120 °C, rapid quenched | Standard supply condition for plate, pipe, tube, bar and forgings; maximum corrosion resistance and ductility for nuclear/pressure service. | 290 | 620 | 50 | 160 HB | — |
880–930 °C hold after solution anneal | Chosen for severe hot nitric-acid or long high-temperature service where all residual carbon must be tied up as NbC. | 300 | 610 | 45 | 165 HB | 2.4 % IACS |
As-welded deposit (ER347 / E347 type filler, no PWHT) | Design basis for weld metal and HAZ in nuclear/piping joints welded without post-weld solution anneal. | 400 | 600 | 35 | 180 HB | 2.3 % IACS |
Cold DrawnThis page Cold drawn / cold finished bar (annealed + drawn) | Bar and tube where tighter tolerance, better surface and higher yield strength are needed than annealed. | 500 | 720 | 30 | 16 HRC | 2.4 % IACS |
Quarter hard | Light cold-rolled temper for springy sheet parts still needing appreciable forming ability. | 545 | 880 | 12 | 25 HRC | 2.4 % IACS |
Half hard | Structural sheet, clamps and springs where strength outweighs formability. | 790 | 1,060 | 10 | 32 HRC | 2.4 % IACS |
Three-quarter hard | High-strength strip for flat springs and shims with only simple bends. | 960 | 1,230 | 7 | 37 HRC | 2.4 % IACS |
heavily cold rolled strip per ASTM A666 | Maximum strength thin strip; essentially no forming beyond flat blanking. | 1,000 | 1,300 | 4 | 40 HRC | 2.4 % IACS |
What is 347LN Cold Drawn?
347LN Cold Drawn is 347LN supplied in the Cold Drawn condition — bar and tube where tighter tolerance, better surface and higher yield strength are needed than annealed. 347LN Cold Drawn has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 77% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 195 GPa (28.3 Msi). 347LN Cold Drawn has a density of 7.95 g/cm³ (0.287 lb/in³), heavier than 81% of stainless steel grades. It melts at 1,400°C (2,552 °F). Annealed is the default condition FabDigit quotes; Cold Drawn is available on request or by drawing note.
Advantages
- Readily welded — 85/100, better than 87% of stainless steel grades
- High strength — 500 MPa (72.5 ksi), better than 77% of stainless steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
347LN Cold Drawn properties
Typical room-temperature values for 347LN Cold Drawn; 24 are specific to this condition. Other listed values are 347LN reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
347LN Cold Drawn has a density of 7.95 g/cm³ (0.287 lb/in³), heavier than 81% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
347LN Cold Drawn has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 77% of stainless steel grades. Elongation at break is 30% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
347LN Cold Drawn is rated for continuous service to 300°C (572 °F). It conducts heat at 16.2 W/m·K (9.36 BTU/hr·ft·°F), better than 64% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
347LN Cold Drawn conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (67/100), better than 61% of stainless steel grades.
Sustainability4
Producing a kilogram of 347LN Cold Drawn takes about 53 MJ of energy and emits 5.2 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 60%.
Manufacturability8
347LN Cold Drawn's machinability is fair (42/100, better than 79% of stainless steel grades); weldability excellent (85/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 347LN Cold Drawn
Is 347LN easy to machine?
Cut like 347/321 — rigid setups, sharp positive-rake carbide, heavy flood coolant, 20–30 % lower speed than 304 because NbC particles are abrasive and chips are stringy.
Can 347LN be welded?
Excellent: GTAW/GMAW/SMAW with ER347/E347 (or Nb-free 316L only where allowed); low heat input, interpass ≤150 °C, no post-weld anneal needed thanks to ultra-low C plus Nb.
Can 347LN be formed, bent or molded?
Very ductile hot (1150–1250 °C) and cold, but work-hardens fast — allow for springback, use interstage anneals for deep draws and avoid stopping hot work below ~900 °C.
What surface finishes work on 347LN?
Pickle (HNO₃/HF) or electropolish after fabrication and passivate per ASTM A967; polishes to a mirror finish; never anodised, and avoid iron contamination from carbon-steel tooling.
347LN 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 |
|---|---|---|
| Cultra-low carbon, controlled range | 0.01 – 0.02 | 0.01 |
| Nnitrogen-strengthened | 0.06 – 0.1 | 0.08 |
| Cr | 17 – 19 | 18 |
| Ni | 9 – 13 | 10.5 |
| Nbstabiliser; standard requires ≥15×C (Nb+Ta basis in some specs) | 0.2 – 1 | 0.4 |
| Mn | ≤ 2 | 1.5 |
| Si | ≤ 1 | 0.5 |
| P | ≤ 0.05 | — |
| Snuclear orders often restrict S ≤0.015 and Co ≤0.05 | ≤ 0.03 | — |
| Fe | balance | — |
347LN Cold Drawn — frequently asked
What is 347LN Cold Drawn used for?
347LN Cold Drawn is typically used for nuclear primary and secondary piping, high-pressure welded piping systems, superheater and reheater tubing, pressure vessel shells and nozzles, steam headers and manifolds and welded expansion joints and bellows. In short: stabilized, sensitization-resistant 347; nitrogen-boosted weld strength; nuclear-grade piping choice.
What is the yield strength of 347LN Cold Drawn?
347LN Cold Drawn has a typical yield strength of 500 MPa (72.5 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 77% of stainless steel grades. Strength varies by condition: see the 8 listed tempers.
Is 347LN Cold Drawn easy to machine?
Not especially — machinability is rated fair (42/100, better than 79% of stainless steel grades). Cut like 347/321 — rigid setups, sharp positive-rake carbide, heavy flood coolant, 20–30 % lower speed than 304 because NbC particles are abrasive and chips are stringy.
Can 347LN Cold Drawn be welded?
Yes — weldability is rated excellent (85/100). Excellent: GTAW/GMAW/SMAW with ER347/E347 (or Nb-free 316L only where allowed); low heat input, interpass ≤150 °C, no post-weld anneal needed thanks to ultra-low C plus Nb.
What surface finishes work on 347LN Cold Drawn?
Pickle (HNO₃/HF) or electropolish after fabrication and passivate per ASTM A967; polishes to a mirror finish; never anodised, and avoid iron contamination from carbon-steel tooling.
Can 347LN Cold Drawn be formed, bent or molded?
Very ductile hot (1150–1250 °C) and cold, but work-hardens fast — allow for springback, use interstage anneals for deep draws and avoid stopping hot work below ~900 °C.
What is the maximum service temperature of 347LN Cold Drawn?
347LN Cold Drawn 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.
Sources
- ASTM A240/A240M — Chromium and Chromium-Nickel Stainless Steel Plate, Sheet and Strip (UNS S34751) — ASTM International (2023)
- ASTM A312/A312M — Seamless and Welded Austenitic Stainless Steel Pipes — ASTM International (2022)
- ASTM A666 — Annealed or Cold-Worked Austenitic Stainless Steel Sheet, Strip, Plate and Flat Bar — ASTM International (2015)
- ASME BPVC Section II Part D — Material Properties (physical/allowable stress tables for 347 group) — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- EN 10088-2 / 1.4550 (X6CrNiNb18-10) stabilised austenitic stainless — CEN (2014)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.