201
Typical reasons to choose 201
- Household appliances
- Kitchen utensils
- Sinks in mild environments
- Doors and windows
- Railroad cars
- High-strength formed sheet parts
Stainless steel grade comparison
201 vs 317L Stainless Steel
Compare 201 and 317L stainless steel by chemistry, mechanical strength, molybdenum content, pitting resistance, chloride performance, chemical-process suitability, fabrication, product forms and procurement cost.
Quick answer:
choose 201 for economical high-strength formed parts
in mild environments. Choose 317L when chemical exposure,
chlorides or localized corrosion justify a higher-alloy
austenitic grade with approximately 3% molybdenum
and a PRE around 28.
The alloy difference behind the selection
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
317L
EN 1.4438 · UNS S31703
- Structure Austenitic
- Typical Cr 18.2%
- Typical Ni 11.6%
- Typical Mo 3.1%
- Typical C 0.02%
- PRE ≈28
Typical chemistry basis: Outokumpu Core 201/4372 and Ultra 317L. Grade chemistry on the actual order must be verified against the applicable specification and material certificate.
M03 · Decision summary
201 or 317L stainless steel: which one should you specify?
201 and 317L are both austenitic stainless steels, but their alloy strategies are very different. 201 prioritizes strength and reduced nickel content; 317L increases chromium, nickel and especially molybdenum to improve resistance in more aggressive wet-corrosion environments.
Decision first:
use 201 when high strength, forming and material economy
are the primary requirements and corrosion exposure is mild.
Use 317L where chemical processing, chloride exposure,
pitting or crevice corrosion risk makes a 3% Mo
austenitic grade worthwhile.
Best for 201
High-strength economical sheet
Strong proof strength and work hardening make 201 attractive for formed components where the environment does not require a high-Mo alloy.
Best for 317L
Aggressive wet-corrosion service
The approximately 3.1% Mo content raises pitting resistance and supports use in chemical, petrochemical, pulp and paper applications.
Recommendation reverser
317L is not the end of the alloy ladder
Hot seawater, severe crevices, very high chlorides or aggressive acids can still require duplex, 904L, 6% Mo or another higher-alloy material.
| Decision factor | 201 stainless steel | 317L stainless steel |
|---|---|---|
| Room-temperature strength |
High proof strength and high work hardening.
Strength advantage |
Lower annealed yield requirement; not selected primarily for maximum strength. |
| PRE | Approximately 17. |
Approximately 28.
Corrosion advantage |
| Molybdenum | No intentional Mo addition. |
Approximately 3.1% Mo.
Local corrosion resistance |
| Chemical processing | Only after confirming that the environment is sufficiently mild. |
Established application family.
Preferred |
| Chloride resistance | Limited compared with Mo-alloyed grades. |
Higher resistance to pitting
and crevice corrosion.
Advantage |
| Forming |
High ductility combined with
very strong work hardening.
Strong forming route |
Good austenitic formability, but higher alloying increases material cost. |
| Oil & gas / process equipment | Environment-specific review required. | Common application family for corrosion-resistant equipment. |
| Relative alloy cost |
Lower Ni and no Mo usually provide
a lower alloy-cost structure.
Cost advantage |
Higher Cr, Ni and about 3% Mo create a materially higher alloy cost. |
Selection rule:
start with 201 when mechanical strength and cost
are the main constraints. Move toward 317L only when
the corrosion environment gives the extra chromium,
nickel and molybdenum a measurable service-life benefit.
M04 · Technical data
201 vs 317L stainless steel properties
201 and 317L should not be compared from one tensile number alone. 201 is optimized around room-temperature strength and work hardening, while 317L earns its position primarily through higher Cr-Ni-Mo alloying and corrosion resistance.
Typical chemical composition
Typical manufacturer values by mass. Use the governing standard and MTC for final heat acceptance.
| Element / indicator | 201 / S20100 | 317L / S31703 | Selection significance | Data basis |
|---|---|---|---|---|
| Carbon, C | 0.05% | 0.02% | 317L is a low-carbon grade suited to welded corrosion-resistant fabrication. | Typical manufacturer chemistry |
| Chromium, Cr | 16.1% | 18.2% | 317L carries a higher chromium level to support the passive film. | Outokumpu typical values |
| Nickel, Ni | 3.6% | 11.6% | 201 deliberately reduces nickel; 317L uses a conventional high-Ni austenitic corrosion-resistant chemistry. | Outokumpu typical values |
| Molybdenum, Mo | Not intentionally alloyed | 3.1% | This is the major difference for pitting and crevice-corrosion resistance. | Outokumpu typical values |
| Manganese, Mn | 6.6% | Conventional Cr-Ni-Mo level | High manganese is central to 201's low-Ni alloy design. | Grade design |
| Nitrogen, N | 0.08% | Low / specification-controlled | Nitrogen contributes to 201's elevated room-temperature strength. | Typical / standard basis |
| PRE | ≈17 | ≈28 | 317L has the clearly higher composition-based pitting-resistance indicator. | Cr + 3.3Mo + 16N |
Room-temperature mechanical comparison
Keep the applicable standard visible. EN and ASTM minima are not interchangeable.
| Property | 201 | 317L | Condition / standard | Interpretation |
|---|---|---|---|---|
| Rp0.2 | 350 MPa | 240 MPa | EN 10088-2 cold-rolled reference | 201 has the higher cold-rolled room-temperature proof strength. |
| Rp1.0 | 380 MPa | 270 MPa | EN 10088-2 cold-rolled reference | 201 maintains a substantial strength advantage. |
| Tensile strength | 680–880 MPa | Not stated for cold roll in cited EN table | EN cold-rolled reference | Do not invent an EN cold-roll tensile range where the cited table does not provide one. |
| Minimum elongation | 45% | 35% | EN cold-rolled reference | Both are ductile austenitic steels, while 201 combines ductility with stronger work hardening. |
| ASTM minimum yield strength | 269 MPa | 205 MPa | ASTM A240 | 201 has the higher stated minimum yield requirement. |
| ASTM minimum tensile strength | 515 MPa | 515 MPa | ASTM A240 | Identical minimum tensile values do not imply identical work-hardening or corrosion behavior. |
| ASTM elongation | 40% | 40% | ASTM A240 reference | Both meet a high ductility requirement in this specification framework. |
317L product-condition properties
EN references vary by product form, which is why grade-only comparisons should not ignore delivery condition.
| 317L form | Rp0.2 | Rp1.0 | Rm | Minimum elongation |
|---|---|---|---|---|
| Cold rolled | 240 MPa | 270 MPa | Not stated in cited table | 35% |
| Hot rolled | 220 MPa | 260 MPa | Not stated in cited table | 35% |
| Quarto plate | 220 MPa | 260 MPa | 520–720 MPa | 40% |
317L elevated-temperature strength
Minimum EN reference values. These numbers do not convert 317L into a dedicated furnace alloy.
| Temperature | Rp0.2 | Rp1.0 | Tensile strength | Design note |
|---|---|---|---|---|
| 100°C | 172 MPa | 206 MPa | 430 MPa | Minimum published reference. |
| 200°C | 147 MPa | 177 MPa | 390 MPa | Strength decreases with temperature. |
| 300°C | 127 MPa | 156 MPa | 380 MPa | Confirm design code and allowable stress. |
| 400°C | 115 MPa | 144 MPa | Not stated in cited table | Temperature-dependent data becomes critical. |
| 500°C | 110 MPa | 138 MPa | Not stated in cited table | Review long-duration service, creep and applicable design standard. |
Typical physical properties
Metric values at or near 20°C unless otherwise noted.
| Property | 201 | 317L | Condition | Engineering effect |
|---|---|---|---|---|
| Density | 7.8 kg/dm³ | 8.0 kg/dm³ | Reference value | 317L is slightly denser. |
| Elastic modulus | 200 GPa | 200 GPa | 20°C | Same cited stiffness. |
| Thermal expansion | Not stated in cited Core table | 16.0 ×10⁻⁶/K | 20–100°C | Use approved project data for thermal movement. |
| Thermal conductivity | 15 W/m·K | 14 W/m·K | 20°C | Very similar low conductivity. |
| Specific heat | Not stated in cited Core table | 500 J/kg·K | 20°C | Use a verified 201 value if heat-capacity calculations are required. |
| Electrical resistivity | 0.70 Ω·mm²/m | 0.85 Ω·mm²/m | 20°C | 317L has the higher cited resistivity. |
| Magnetizable | No* | No* | Annealed classification | Cold work can alter actual magnetic response in austenitic steels. |
Key comparison:
201 offers the stronger room-temperature strength proposition.
317L offers the stronger corrosion proposition.
The approximately 3.1% Mo content and PRE around 28
are the main reasons to pay the 317L alloy premium.
M05 · Product form matrix
Product forms and supply routes for 201 and 317L
201 is primarily supplied for economical flat-product applications. 317L is commonly available through cold-rolled, hot-rolled and quarto plate routes for corrosion-resistant process equipment.
Availability note:
these are typical product routes,
not a statement of current warehouse inventory.
Confirm grade, thickness, width,
finish, quantity and certificate requirements.
| Product form | 201 | 317L | Procurement note |
|---|---|---|---|
| Cold-rolled coil & sheet | Common | Available | Established route for both grades. |
| Hot-rolled coil & sheet | Available | Available | Confirm surface and annealed condition. |
| Quarto plate | Verify source | Published route | 317L is established in heavy corrosion-resistant plate. |
| Precision strip | Source-dependent | Confirm mill program | Gauge and temper availability varies. |
| Pipe / tube | Specification-dependent | Supplier-dependent | Confirm tubular standard, OD, wall and heat treatment. |
| Chemical process equipment | Environment review | Typical use | 317L is specifically associated with chemical processing. |
| Pulp & paper equipment | Not primary route | Typical use | Mo alloying is valuable in many process-corrosion conditions. |
| Bright / smooth cold-rolled finish | Available | Available by route | Confirm finish together with thickness and mill source. |
M06 · Grade selector
Use strength and corrosion severity to choose 201 or 317L
The largest decision difference is whether the component needs 201's strength advantage or 317L's much greater Cr-Ni-Mo corrosion alloying.
Preliminary result
Start with 317L
If corrosion severity is an important unknown, 317L is the stronger corrosion-oriented starting point between these two because of its higher Cr, Ni and approximately 3.1% Mo content.
Send Conditions to an Engineer
STEP 01
Define chemistry
Chlorides, acids, pH, process chemicals and contaminants.
STEP 02
Define temperature
Higher temperature can accelerate localized and general corrosion.
STEP 03
Define fabrication
Forming, welding, heat tint, pickling and final surface condition.
STEP 04
Define strength
Required yield, cold work, thickness and finished condition.
M08 · Applications & limitations
Where 201 works, where 317L earns its premium, and where neither grade is enough
201 is primarily a high-strength, economical formed-product grade. 317L is primarily a corrosion-resistant process grade where increased molybdenum provides measurable service benefit.
317L
Typical reasons to choose 317L
- Chemical processing equipment
- Petrochemical equipment
- Pulp and paper equipment
- Oil and gas applications
- Condenser and heat-exchanger service
- Flue-gas desulfurization equipment
!
Conditions requiring a higher-alloy review
- Warm or hot seawater
- Very high chloride concentration
- Stagnant crevices and deposits
- Strong reducing or oxidizing acids
- Chloride SCC conditions
- Known 317L corrosion failures
Failure modes that can reverse the recommendation
Why can 201 pit before 317L?
201 has no intentional molybdenum addition
and a PRE around 17. 317L contains about 3% Mo
and has a PRE around 28, giving its passive film
a stronger alloy basis against localized corrosion.
Can 317L still pit in chloride service?
Yes. PRE is a useful screening indicator,
not a guarantee. Chloride concentration,
temperature, deposits, crevices, surface finish
and oxidizing conditions can still cause attack.
Can 317L suffer chloride stress-corrosion cracking?
Yes. Like other conventional austenitic
Cr-Ni-Mo steels, 317L can remain susceptible
to chloride SCC when tensile stress,
temperature and chloride exposure combine.
Why does surface condition matter?
Rough surfaces, weld heat tint,
iron contamination, deposits and poorly
treated welds can reduce practical corrosion
performance even when the base alloy is appropriate.
When should 904L or 6% Mo be considered?
If chloride, acid concentration or process
temperature moves beyond the demonstrated
317L envelope, higher-alloy austenitic,
duplex or nickel-containing materials
should be evaluated.
Why can 201 still be more economical?
Where the environment is mild,
317L's additional chromium, nickel and
molybdenum may add cost without providing
a necessary service-life benefit.
Important:
317L provides significantly greater localized-corrosion
alloying than 201, but it is not automatically
suitable for every chloride or acid environment.
Material image comparison
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M10 · Standards & equivalence
201 and 317L stainless steel grade designations
The grades are both austenitic, but 201 belongs to the low-nickel Cr-Mn family while 317L belongs to the high-Mo Cr-Ni-Mo corrosion-resistant family.
| Designation system | 201 | 317L | Procurement note |
|---|---|---|---|
| ASTM / AISI type | 201 | 317L | Common grade names. |
| UNS | S20100 | S31703 | Use UNS for precise alloy identification. |
| EN material number | 1.4372 | 1.4438 | European references commonly associated with these grades. |
| Microstructure | Austenitic | Austenitic | Same structure does not imply equivalent corrosion resistance. |
| Alloy family | Low-Ni Cr-Mn-N | Low-carbon Cr-Ni-Mo | The Mo content is a major difference. |
| PRE | ≈17 | ≈28 | A composition indicator, not a universal corrosion guarantee. |
| ASTM A240/A240M | Flat-product reference | Flat-product reference | Confirm current edition and required delivery condition. |
| EN 10088-2 | Flat-product mechanical reference | Product-condition reference | Values differ for cold roll, hot roll and plate. |
| JIS / GB cross-reference | Verify against purchase standard | Verify against purchase standard | Do not approve substitution from an informal equivalence chart alone. |
ASTM A240/A240M
Flat-product specification reference
for plate, sheet and strip.
EN 10088-1
Designation and physical-property
reference family.
EN 10088-2
Technical delivery and mechanical-property
reference for stainless flat products.
EN 10028-7
Reference basis for selected
elevated-temperature mechanical properties.
A cross-standard designation does not by itself prove interchangeability. Confirm chemistry, mechanical condition, product form, dimensions, corrosion environment and the exact standard revision.
M11 · Direct answers
201 vs 317L stainless steel FAQ
Direct answers to common engineering and purchasing questions about 201 versus 317L stainless steel.
What is the main difference between 201 and 317L?
201 is a low-nickel Cr-Mn-N austenitic grade focused on high strength and economical forming. 317L is a low-carbon Cr-Ni-Mo austenitic grade with about 3% molybdenum for substantially greater localized-corrosion resistance.
Which is stronger at room temperature?
201 has the stronger room-temperature yield-strength proposition. The cited EN cold-rolled value is 350 MPa Rp0.2 for 201 versus 240 MPa for 317L.
Which has better corrosion resistance?
317L. Its higher chromium and approximately 3.1% molybdenum produce a PRE around 28, compared with approximately 17 for 201.
Is 317L better than 316L?
317L generally provides higher localized-corrosion resistance because it contains more molybdenum and typically somewhat more chromium than 316L. Whether that advantage is needed depends on the actual environment and total cost.
Is 317L suitable for seawater?
It provides greater chloride resistance than 201 and standard 316L, but hot or stagnant seawater, crevices and high chloride concentrations can still exceed its capability. Duplex or higher-alloy stainless steels may be more appropriate.
Why is 317L more expensive than 201?
317L contains substantially more nickel, chromium and roughly 3% molybdenum. 201 deliberately reduces nickel and contains no intentional molybdenum addition, so its alloy-cost structure is normally lower.
Can 317L be welded?
Yes. 317L is a low-carbon austenitic grade and can be welded using suitable stainless welding procedures and compatible consumables. Weld cleaning and heat-tint removal remain important for corrosion-critical equipment.
Can 201 replace 317L?
Only if the real service environment proves that 317L's molybdenum-based corrosion resistance is unnecessary. 201 having higher room-temperature strength is not enough to justify substitution in a corrosion-critical process application.
M13 · Sources & technical review
Technical basis for this 201 vs 317L comparison
The comparison separates alloy chemistry, room-temperature strength, localized-corrosion indicators and elevated-temperature data so the recommendation does not rely on one isolated property.
Primary technical references
- Outokumpu Core Range Datasheet 201/4372 chemistry, PRE, mechanical properties, physical properties, product forms and applications.
- Outokumpu Core 201/4372 Product Information Low-nickel Cr-Mn chemistry, high work hardening, strength and application guidance.
- Outokumpu Ultra Range Datasheet 317L chemistry, PRE, product forms, room-temperature properties, elevated-temperature properties and physical data.
- Aperam 317L / 1.4438 Product Data Independent manufacturer reference for approximately 3% Mo chemistry, product dimensions and applications.
- ASTM A240/A240M Plate, sheet and strip mechanical-property reference.
- EN 10088-1 / EN 10088-2 Designation, physical property and flat-product mechanical references.
- EN 10028-7 Basis for selected elevated-temperature property values.
Page accountability
Author
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Add the real person responsible for the material-selection and procurement content.
Technical reviewer
[Technical reviewer name]
Add a real reviewer with materials, corrosion or metallurgy credentials.
Review date
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Set this only after the technical review has actually been completed.
Review scope
Chemistry · corrosion · strength · fabrication
Confirm the numeric tables, standard conditions, PRE interpretation and application limits.
Update note
Initial T09 comparison prepared with condition-labelled mechanical data, 317L elevated-temperature references, PRE comparison, failure modes and interactive material selector.
M14 · Ask an engineer
Still deciding between 201 and 317L?
Send the actual corrosion environment, mechanical requirement and fabrication details so the material can be screened against the finished component rather than grade name alone.
- 201, 317L or alternative grade under consideration
- Sheet, coil, plate, pipe, tube or fabricated component
- Thickness, width, OD, wall and tolerances
- Required yield or tensile strength
- Cold forming and work-hardening requirements
- Welding process and filler requirement
- Operating temperature
- Chloride concentration
- pH and process chemistry
- Acid type and concentration
- Crevices, deposits or stagnant zones
- Cleaning and wash-down chemicals
- Surface finish and weld-cleaning requirement
- Applicable ASTM, EN or customer specification
- Quantity, destination, due date and MTC requirement
Send your material requirement
For 317L applications, include chloride concentration, process chemistry, temperature, product dimensions, welding, finish and required service life.