201
Typical reasons to choose 201
- Household appliances
- Kitchen utensils
- Sinks in suitable mild environments
- Doors and windows
- Railroad cars
- High-strength formed sheet parts
Stainless steel grade comparison
201 vs 347 Stainless Steel
Compare 201 and 347 stainless steel by chemistry, room-temperature strength, niobium stabilization, intergranular corrosion resistance, intermittent high-temperature service, welding, corrosion behavior, product forms and procurement cost.
Quick answer:
choose 201 when high room-temperature strength,
rapid work hardening and lower nickel content matter
in a mild environment. Choose 347 when welded fabrication,
intergranular corrosion resistance or intermittent
thermal exposure requires a niobium-stabilized
Cr-Ni stainless steel.
The alloy strategy behind the decision
201
EN 1.4372 · UNS S20100
- Structure Austenitic
- Typical Cr 16.1%
- Typical Ni 3.6%
- Typical Mn 6.6%
- Typical N 0.08%
- PRE ≈17
347
EN 1.4550 · UNS S34700
- Structure Austenitic
- Typical Cr 17.5%
- Typical Ni 9.5%
- Typical Nb 0.60%
- Stabilization Niobium
- PRE ≈18
Technical basis: Outokumpu Core 201/4372 and Core 347/4550. Typical chemistry is shown for comparison; the governing specification and MTC control final material acceptance.
M03 · Decision summary
201 or 347 stainless steel: which one should you specify?
201 and 347 are both austenitic stainless steels, but they solve different engineering problems. 201 uses manganese and nitrogen to reduce nickel while achieving high strength. 347 uses niobium stabilization to improve resistance to intergranular corrosion and maintain useful mechanical performance through repeated thermal exposure.
Decision first:
use 201 where room-temperature strength,
work hardening and alloy-cost control dominate
and the environment is mild. Use 347 where
welding, sensitization risk or intermittent exposure
in approximately the 400–900°C range makes
niobium stabilization valuable.
Best for 201
High-strength economical forming
201 offers substantially higher annealed proof strength and rapid work hardening while reducing nickel alloying.
Best for 347
Welded and intermittently heated parts
Niobium stabilization helps 347 maintain intergranular-corrosion resistance after welding and relevant thermal exposure.
Recommendation reverser
High chlorides or long-term creep
347 is not molybdenum alloyed. Severe chloride service may require 316L, duplex or a higher-alloy grade; long-duration creep service may instead point toward 347H.
| Decision factor | 201 stainless steel | 347 stainless steel |
|---|---|---|
| Room-temperature strength |
High proof and tensile strength.
Strength advantage |
Lower annealed strength; selected primarily for stabilization, welding and thermal service. |
| Stabilizing element | No deliberate Nb stabilization. |
Niobium stabilized.
347 advantage |
| Intergranular corrosion | Welding and thermal history require application-specific review. |
Designed to resist sensitization-related
intergranular corrosion.
Preferred |
| Intermittent 400–900°C heating | Not the normal selection basis for 201. |
A specifically identified
Core 347 application window.
Relevant |
| Long-term creep | Use a dedicated high-temperature alloy review. | For long-duration creep-critical service, evaluate 347H rather than assuming standard 347 is sufficient. |
| Chloride pitting | PRE approximately 17. | PRE approximately 18. Neither grade contains intentional molybdenum for a major chloride advantage. |
| Welding | Weldable with appropriate procedure and corrosion review. |
Can be welded across product dimensions
without becoming susceptible
to intergranular corrosion.
Stabilized |
| Machining | High work hardening requires rigid tooling and controlled cutting. | Conventional austenitic machining behavior; work hardening still requires attention. |
| Relative alloy cost |
Lower nickel content normally
provides a lower alloy-cost structure.
Cost advantage |
Higher nickel and stabilized Cr-Ni chemistry generally create higher alloy cost. |
Selection rule:
do not pay for 347 solely because
it carries a higher grade number.
Specify it when niobium stabilization,
welding or thermal exposure provides
a real engineering benefit.
M04 · Technical data
201 vs 347 stainless steel properties
The room-temperature table compares the same EN 10088-2 cold-rolled condition. Niobium stabilization and temperature suitability are kept separate because they cannot be inferred from tensile strength alone.
Typical chemical composition
Typical manufacturer values by mass. Final purchase acceptance must follow the relevant product specification and material test certificate.
| Element / indicator | 201 / S20100 | 347 / S34700 | Selection significance | Basis |
|---|---|---|---|---|
| Carbon, C | 0.05% | 0.05% | 347 uses niobium stabilization to control sensitization rather than relying solely on low carbon. | Typical manufacturer chemistry |
| Chromium, Cr | 16.1% | 17.5% | 347 has somewhat higher typical chromium content. | Outokumpu typical chemistry |
| Nickel, Ni | 3.6% | 9.5% | 201 replaces a large portion of nickel with manganese and nitrogen. | Outokumpu typical chemistry |
| Manganese, Mn | 6.6% | Conventional Cr-Ni level | High Mn is characteristic of the 200-series design. | Grade design |
| Nitrogen, N | 0.08% | Not a primary alloying feature | Nitrogen contributes to the higher strength of 201. | Typical chemistry |
| Niobium, Nb | Not intentionally stabilized | Approx. 0.60% | Niobium is the defining stabilizing addition in 347. | Outokumpu typical chemistry |
| Molybdenum, Mo | No intentional addition | No intentional addition | Neither grade receives a 316-style molybdenum pitting-resistance advantage. | Grade chemistry |
| PRE | ≈17 | ≈18 | 347 is slightly higher, but both remain in the standard Cr-Ni corrosion range. | Manufacturer product-range basis |
Mechanical properties at 20°C
EN 10088-2 cold-rolled coil / sheet values for an equivalent condition comparison.
| Property | 201 / 1.4372 | 347 / 1.4550 | Condition | Interpretation |
|---|---|---|---|---|
| 0.2% proof strength | 350 MPa | 220 MPa | Cold-rolled coil / sheet | 201 has the clear room-temperature yield-strength advantage. |
| 1.0% proof strength | 380 MPa | 250 MPa | Cold-rolled coil / sheet | 201 remains substantially stronger. |
| Tensile strength | 680–880 MPa | 520–720 MPa | Cold-rolled coil / sheet | 201 has the higher published tensile range. |
| Elongation | 45% | 40% | EN cold-rolled condition | Both remain ductile austenitic grades. |
| Work hardening | High | Typical austenitic behavior | Fabrication dependent | 201 gains strength rapidly during cold deformation. |
347 mechanical properties by flat-product condition
The same grade has different EN minima depending on cold-rolled, hot-rolled or quarto-plate condition.
| 347 product form | Rp0.2 | Rp1.0 | Rm | Elongation |
|---|---|---|---|---|
| Cold rolled coil / sheet | 220 MPa | 250 MPa | 520–720 MPa | 40% |
| Hot rolled coil / sheet | 200 MPa | 240 MPa | 520–720 MPa | 40% |
| Quarto plate | 200 MPa | 240 MPa | 500–700 MPa | 40% |
Temperature and stabilization comparison
Use temperature ranges as selection guidance, not as an automatic allowable-stress table.
| Condition | 201 | 347 | What it means | Engineering action |
|---|---|---|---|---|
| Room-temperature structural strength | Strong advantage | Normal austenitic range | 201 is normally the stronger annealed grade at room temperature. | Compare final thickness and forming condition. |
| Intermittent thermal exposure | Not primary selection basis | 400–900°C identified application range | 347 is specifically used where repeated heating makes stabilization valuable. | Confirm dwell time and cycles. |
| Welding + sensitization risk | Procedure-dependent | Nb stabilized | 347 is designed to retain resistance to intergranular corrosion after relevant welding heat input. | Confirm filler and weld treatment. |
| Long-duration creep service | Alternative alloy review | Evaluate 347H | Standard 347 and 347H should not be treated as identical high-temperature grades. | Use design-code creep data. |
| 347H reference window | Not applicable | Long-term creep optimized around 550–600°C | Relevant where sustained high-temperature strength governs. | Specify 347H deliberately when required. |
Typical physical properties
Metric values according to the cited Core / EN reference data.
| Property | 201 | 347 | Condition | Engineering effect |
|---|---|---|---|---|
| Density | 7.8 kg/dm³ | 7.9 kg/dm³ | Reference value | 347 is slightly denser. |
| Elastic modulus | 200 GPa | 200 GPa | 20°C | Essentially the same elastic stiffness. |
| Thermal expansion | Verify for project calculation | 16.0 ×10⁻⁶/K | 20–100°C for 347 | Use verified condition-specific values for thermal movement. |
| Thermal conductivity | 15 W/m·K | 15 W/m·K | 20°C | Same cited room-temperature value. |
| Specific heat | Verify for project calculation | 500 J/kg·K | 20°C | Do not invent a missing 201 design value. |
| Electrical resistivity | 0.70 Ω·mm²/m | 0.73 Ω·mm²/m | 20°C | The values are close. |
| Magnetizable | No* | No* | Annealed classification | Cold deformation can change actual magnetic response, especially in metastable austenitic steel. |
Key point:
201 wins the room-temperature strength comparison.
347 wins the stabilization and intermittent
high-temperature comparison. Its niobium addition
does not create a 316-style molybdenum advantage
in chloride pitting resistance.
M05 · Product form matrix
Product forms and supply routes for 201 and 347
201 is primarily associated with hot- and cold-rolled flat products. 347 has established flat-product routes and is also specified in selected high-temperature tube, forging, flange and pressure-component standards.
Availability note:
this matrix describes typical
commercial product routes only.
It does not state live inventory.
Confirm the actual grade, form,
dimension, finish, standard and certification.
| Product form / condition | 201 | 347 | Procurement note |
|---|---|---|---|
| Cold-rolled coil & sheet | Common | Common | Established flat-product route for both grades. |
| Hot-rolled coil & sheet | Common | Common | Confirm annealed / pickled surface condition and dimensions. |
| Quarto plate | Verify mill route | Published route | 347 is established in thicker stabilized plate applications. |
| Precision strip | Source-dependent | Confirm source | Specify gauge, temper, edge and surface finish. |
| Seamless high-temperature tube | Not primary route | Product-specific route | 347 / 347H tubular products are available under applicable high-temperature standards. |
| Flanges / forgings | Not primary route | Established application | Confirm forging specification and whether F347 or F347H is required. |
| Exhaust / expansion components | Environment-dependent | Typical use | 347 is used in expansion joints and exhaust manifolds. |
| High-temperature gaskets | Not primary selection | Typical use | Temperature cycle, load and oxidation environment still require review. |
| Chemical production equipment | Environment review | Established use | Do not assume 347 is suitable for severe chloride chemistry. |
M06 · Grade selector
Use strength, welding and thermal exposure to choose 201 or 347
Check the actual design conditions below. The result provides a preliminary material direction, not final engineering approval.
Preliminary result
Start with 347
If welding or repeated thermal exposure is part of the application, 347 is normally the stronger starting point because niobium stabilization addresses a service requirement that 201 does not.
Send Conditions to an Engineer
STEP 01
Define temperature
Normal, peak, continuous, intermittent and cyclic temperature.
STEP 02
Define welding
Joint type, section thickness, heat input, filler and post-weld condition.
STEP 03
Define corrosion
Water, chlorides, acids, condensate and process chemicals.
STEP 04
Define strength
Yield requirement, cold work, thickness and final condition.
M08 · Applications & limitations
Where 201 works, where 347 earns its premium, and where neither grade is enough
201 is mainly a high-strength and economical formed-product grade. 347 becomes relevant when niobium stabilization, welding or repeated thermal exposure provides a measurable service-life benefit.
347
Typical reasons to choose 347
- High-temperature gaskets
- Rocket engine parts
- Expansion joints
- Aircraft collector rings
- Exhaust manifolds
- Chemical production equipment
- Flanges and valves
!
Conditions requiring another alloy review
- Hot concentrated chlorides
- Warm seawater with stagnant crevices
- Chloride SCC conditions
- Strong acid service
- Long-duration creep-critical operation
- High-temperature oxidation beyond the grade envelope
Failure modes that can reverse the recommendation
Why is niobium added to 347?
Niobium preferentially combines with carbon,
reducing chromium-carbide precipitation
at grain boundaries. This helps preserve
chromium in the surrounding matrix and improves
resistance to sensitization-related
intergranular corrosion.
Is 347 significantly more chloride resistant than 201?
Not by the same mechanism as 316L or 317L.
The cited PRE values are approximately
17 for 201 and 18 for 347.
Neither contains intentional molybdenum,
so severe chloride exposure can require
a different grade.
Can 347 be welded?
Yes. The stabilized chemistry is specifically
useful for welded fabrication.
Welding procedure, filler selection,
heat tint removal and final surface treatment
still influence real corrosion performance.
Why is 347 useful between 400 and 900°C?
Niobium stabilization helps control
sensitization during thermal exposure,
and the grade retains useful mechanical
properties at elevated temperature.
Manufacturer guidance specifically identifies
intermittent heating in this range.
When should 347H be considered instead?
When long-duration elevated-temperature
strength and creep become design drivers,
347H should be reviewed separately.
It is not appropriate to treat standard
347 and 347H as identical materials.
Why might 201 still be the better choice?
If the component operates at moderate
temperature in a mild environment
and primarily needs strength,
347's stabilization and higher nickel
content may add cost without solving
a real engineering problem.
Important:
347's niobium addition improves
intergranular-corrosion behavior,
but it does not make the grade immune
to pitting, crevice corrosion,
chloride SCC or excessive
high-temperature creep.
Material image comparison
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M10 · Standards & equivalence
201 and 347 stainless steel grade designations
201 is a low-nickel Cr-Mn-N austenitic stainless steel. 347 is a niobium-stabilized Cr-Ni austenitic stainless steel. Cross-standard designations remain product- and condition-dependent.
| Designation system | 201 | 347 | Procurement note |
|---|---|---|---|
| ASTM / AISI type | 201 | 347 | Common North American grade designations. |
| UNS | S20100 | S34700 | Useful for precise alloy identification. |
| High-temperature UNS variant | Not applicable | S34709 / 347H | 347H is a separate high-temperature material variant. |
| EN material number | 1.4372 | 1.4550 | European material-number references. |
| EN name | X12CrMnNiN17-7-5 | X6CrNiNb18-10 | Confirm the exact current product standard. |
| JIS reference | SUS201 | SUS347 | JIS availability and requirements vary by product standard. |
| GB reference | 12Cr17Mn6Ni5N | 06Cr18Ni11Nb | Treat these as cross-standard references, not unconditional substitutes. |
| Microstructure | Austenitic | Austenitic | Same broad microstructure does not make the grades equivalent. |
| Alloy concept | Low-Ni Cr-Mn-N | Nb-stabilized Cr-Ni | The stabilizing strategy is a fundamental difference. |
| ASTM A240/A240M | Flat-product reference | Flat-product reference | Confirm the current revision and exact condition. |
| ASTM A213 / A312 | Product-specific verification required | TP347 / TP347H routes available | Tube and pipe requirements are not the same as flat-product requirements. |
| ASTM A182 | Product-specific verification | F347 / F347H | Relevant to forged flanges, fittings and valves. |
| EN 10088-2 | Flat-product reference | Flat-product reference | Mechanical values differ by cold roll, hot roll and plate. |
ASTM A240/A240M
Plate, sheet and strip
reference family.
EN 10088-1 / 2
Grade designation,
physical data and flat-product
mechanical references.
ASTM A213 / A312
Relevant 347 / 347H
tubular specification families.
ASTM A182
F347 / F347H reference
for selected forged components.
Cross-standard grades are approximate until chemistry, mechanical condition, product form, dimensions, heat treatment and the current standard revision all align.
M11 · Direct answers
201 vs 347 stainless steel FAQ
Direct answers to common engineering and procurement questions about 201 versus 347 stainless steel.
What is the main difference between 201 and 347 stainless steel?
201 is a low-nickel Cr-Mn-N austenitic grade focused on high strength and economical forming. 347 is a Cr-Ni austenitic stainless stabilized with niobium for welded and thermally exposed service.
Which is stronger, 201 or 347?
201 is stronger at room temperature in the cited EN cold-rolled condition. Its Rp0.2 is approximately 350 MPa compared with 220 MPa for 347, while the tensile ranges are 680–880 MPa and 520–720 MPa respectively.
Why is niobium added to 347 stainless steel?
Niobium stabilizes carbon, reducing chromium-carbide precipitation at grain boundaries during relevant thermal exposure. This improves resistance to sensitization-related intergranular corrosion.
Is 347 better for welding?
347 is specifically useful for welded fabrication because its niobium stabilization helps retain resistance to intergranular corrosion after welding. Correct filler, weld procedure and surface treatment are still required.
Is 347 more corrosion resistant than 201?
347 belongs to the conventional Cr-Ni stainless family and has a slightly higher basic PRE in the cited data. However, neither grade contains intentional molybdenum, so 347 should not be treated as a 316L-style chloride-resistant upgrade.
What temperature range is 347 used for?
Core 347/4550 is specifically identified for applications involving intermittent heating in approximately the 400–900°C range. Actual allowable service temperature still depends on load, atmosphere, time and the applicable design code.
What is the difference between 347 and 347H?
347H is the high-temperature variant used when sustained creep strength becomes more important. It should be selected deliberately rather than treating standard 347 and 347H as interchangeable.
Is 347 suitable for seawater?
It should not automatically be specified for seawater. 347 has no intentional molybdenum, and warm stagnant chloride environments can require 316L, duplex or a higher-alloy stainless steel.
Can 201 replace 347?
Only if the design does not require 347's niobium stabilization, welded-service behavior or thermal-exposure capability. 201's higher room-temperature strength does not replace the metallurgical function of a stabilized grade.
M13 · Sources & technical review
Technical basis for this 201 vs 347 comparison
This page separates room-temperature strength, wet-corrosion indicators, niobium stabilization, welding and high-temperature service so one property is not incorrectly used as a substitute for another.
Primary technical references
- Outokumpu Core Range Datasheet 201 and 347 chemistry, PRE, EN mechanical values, physical properties, product forms and applications.
- Outokumpu Core 201/4372 Low-nickel Cr-Mn-N alloy design, work hardening, product forms and application guidance.
- Outokumpu Core 347/4550 Niobium stabilization, intergranular-corrosion behavior, 400–900°C intermittent-heating guidance, welding and applications.
- Outokumpu Therma 347H Reference for the separate high-temperature 347H variant and long-term creep applications.
- Alleima 8R40 / 6R44 Technical Data Independent manufacturer reference for Nb-stabilized S34700 / S34709 tube, billet and high-temperature applications.
- ASTM A240/A240M Stainless plate, sheet and strip specification reference.
- EN 10088-1 / EN 10088-2 Designation, physical-property and flat-product mechanical references.
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Update note
Initial T09 comparison prepared with condition-specific mechanical data, niobium-stabilization guidance, temperature reversal conditions, failure modes and RFQ structure.
M14 · Ask an engineer
Still deciding between 201 and 347?
Send the actual temperature, welding, corrosion and strength requirements so the material can be reviewed against the finished component rather than selected from grade name alone.
- 201, 347, 347H or alternative grade under consideration
- Sheet, coil, plate, tube, forging or fabricated component
- Thickness, width, OD, wall and tolerances
- Required room-temperature yield or tensile strength
- Cold forming and work-hardening requirements
- Welding process and filler requirement
- Welded section thickness
- Normal operating temperature
- Peak operating temperature
- Continuous, intermittent or cyclic heat exposure
- Duration at elevated temperature
- Creep or long-term allowable-stress requirement
- Chloride or salt exposure
- Process chemistry and condensate conditions
- Surface finish and weld-cleaning requirements
- Applicable ASTM, ASME, EN, JIS, GB or customer standard
- Quantity, destination, due date and MTC requirement
Send your material requirement
For 347 applications, include thermal cycle, welding details, corrosion exposure, dimensions, product form, standard and required service life.