All About Stainless Steel Types and Grades
A look at the five types of stainless steel along with 35 example grades
There are a few materials out there that have gained so much popularity, they’re essentially household names, and one of those happens to be stainless steel. This well-known family of carbon steel alloys, which is practically the celebrity of metals, can be parsed out into five different groups and then broken down further into a ton of grades. This is what it looks like:
In this article, we break down the different types of stainless steel, as well as an overview of more than 35 grades. If you work with this metal a lot (or plan to) you might want to bookmark this page.
Types of Stainless Steel
All grades of stainless steel fall under one of five different categories: martensitic, austenitic, ferritic, duplex, or precipitation hardened. These types each have a different structure that gives them various properties and benefits (as well as letting you know what they’re not so good at). We’ll explain them in more detail in the table below, but first, a quick note on the structure. If you’d like some more information on how exactly stainless steel is structured, you’re in luck; we wrote a whole guide on this handy metal.
Body-centered tetragonal (BCT): A rectangular cuboid with atoms at each corner and one right in the middle (at the core).
Face-centered cubic (FCC): A cuboid with atoms at each corner, and one in the middle of each face.
Body-centered cubic (BCC): Similar to a BCT, but is a perfectly symmetrical square cube instead of being rectangle.
| Type | Description | Steel Grade | Properties | Applications |
|---|---|---|---|---|
Type Martensitic | Description BCT structure, carbon content up to 1.2%, 10.5–18% of chromium | Steel Grade 403, 410, 414, 431, 422, 420, 416, 440 | Properties Good: heat treatability, ductility, toughness, tensile strength, creep resistance, fatigue resistance, magnetism Fair: work hardening rate | Applications Cutlery, knives, medical instruments, scissors, jet engines |
Type Austenitic | Description FCC structure, up to 0.15% carbon, chromium 16–26%, up to 35% nickel, up to 15% manganese, 0.75–3% silicon, 0.045–2% phosphorus, trace amounts of sulfur, nitrogen, molybdenum, selenium, copper, titanium, cobalt | Steel Grade 201, 202, 205, 301, 302, 303, 304, 305, 308, 309, 310, 314, 316, 317, 321, 330, 347, 348, 384 | Properties Excellent: work hardening rate, weldability Good: ductility, toughness, tensile strength, creep and fatigue resistance Fair: corrosion resistance (up to 650°C), temperature resistance (up to 650°C) | Applications Exhaust systems, hydraulics, cutlery, cookware, pressure vessels |
Type Ferritic | Description BCC structure with 10.5–30% of chromium, no more than 0.2% carbon, and various other alloying elements including molybdenum, silicon, aluminum, and titanium (the last two are necessary for any steel to be classed as ferritic) | Steel Grade 430, 434, 409, 439, 444 | Properties Low work hardening rate Excellent: magnetic response Good: Tensile strength at low temperatures Fair: corrosion resistance, temperature resistance, ductility, toughness Poor: weldability | Applications Ovens, kitchen sinks, solar panel support frames, aqueous chloride solution piping |
Type Duplex | Description FCC and BCC structure, includes up to 26% chromium, 4–7% nickel, up to 4.5% molybdenum, and under 1% of copper, tungsten, nitrogen, and carbon | Steel Grade 2205, 2304, 2507, LDX2101 Four classes: lean duplex, standard duplex, super duplex, hyper duplex | Properties Excellent: corrosion resistance, tensile strength (at moderate temperatures) Good: ductility, toughness, creep resistance, and fatigue resistance (at moderate temperatures) Fair: temperature resistance, weldability, magnetic response Poor: heat treatability | Applications Components for aqueous chloride plants, oil and gas industry environments, seawater desalination plants |
Type Precipitation-hardened | Description Can have either FCC and BCC structure but with particles, has elements like chromium, iron, nickel, aluminum, titanium, and copper | Steel Grade 17-4, 13-8, 15-5 | Properties Can be magnetic or non-magnetic Excellent: tensile and yield strengths, corrosion resistance Good: ductility, toughness, heat treatability Poor: Weldability | Applications Components for marine, aerospace, medical, automotive |
Types of Stainless Steel
In this ultra close-up photo, you can see the ferritic and austenitic structures that make up duplex stainless steel—two types that are explained on the table above.
Stainless Steel Grades
Now that you have an understanding of how stainless steel can be categorized, it’s time to get to know the different grades that exist. But just before, here’s a quick rundown of the naming conventions so you’re aware of what the different groups and grades of steel are called:
- Austenitic: Group A
- Duplex: Group AF
- Ferritic: Group F
- Martensitic: Group C
The below table will show you the grade, the specific composition of that stainless steel broken down by percentage, its properties, and the applications it’s normally used for.
Key
- Carbon: C
- Manganese: Mn
- Silicon: Si
- Chromium: Cr
- Nickel: Ni
- Phosphorus: P
- Sulfur: S
- Nitrogen: N
- Molybdenum: Mb
- Tungsten: W
- Copper: Cu
- Iron: Fe
- Boron: B
- Titanium: Ti
- Selenium: Se
- Niobium: Nb
- Tantalum: Ta
| Grade | Composition % | Properties | Applications |
|---|---|---|---|
Grade 201 | Composition % C: 0.15, Mn: 5.5–7.5, Si: 1, Cr: 16–18, Ni: 3.5–5.5, P: 0.045, S: 0.015, N: 0.25 | Properties Good: ductility, work-hardening rate, weldability, low-temperature resistance Fair: corrosion resistance | Applications Architecture, sinks, cold-formed parts |
Grade 202 | Composition % C: 0.15, Mn: 7.5–10, Si: 1, Cr: 17–19, Ni: 4–6, P: 0.045, S: 0.015, N: 0.25 | Properties Good: ductility, weldability (except through oxyacetylene welding), low-temperature resistance, cold working hardens this metal Fair: corrosion resistance | Applications Sinks, doors, railings, windows, kitchen appliances |
Grade 205 | Composition % Cr: 16.5–18, Mn: 14–15.5, Ni: 1–1.75, N: 0.4 | Properties Good: ductility, work hardening rate, weldability Fair: temperature resistance, corrosion resistance | Applications Cutlery, cookware, decorative architectural and design elements, food and beverage equipment |
Grade 2507 | Composition % Cr: 25, Ni: 7, Mb: 4, N: 0.28, W: 0.7, Cu: 0.7 | Properties Excellent: corrosion resistance, temperature resistance (it has a pitting resistance equivalent number of 43) Good: weldability Fair: work hardening rate, ductility | Applications Parts for coal, pulp, paper, desalination plants |
Grade 301 | Composition % C: 0.05–0.15, Mn: 2, Si: 2, Cr: 16–19, Ni: 6–9.5, P: 0.045, S: 0.015, Ni: 0.11, Mb: 0.8 | Properties Good: ductility, corrosion resistance, temperature resistance (and holds onto its toughness), weldability, work hardening rate | Applications Watch bands, medical instruments, toys, office equipment, eating utensils |
Grade 302 | Composition % C: 0.15, Mn: 2, Si: 1, Cr: 17–19, Ni: 8–10, P: 0.045, S: 0.03 | Properties Excellent: weldability, temperature resistance (and keeps its toughness) Good: work hardening rate, corrosion resistance Fair: ductility | Applications Cold-working, dishwashers, blenders, stamps, cryogenic applications |
Grade 302B | Composition % Cr: 17–19, Ni: 8–10, C: 0.15, Mn: 2, Si: 2–3, P: 0.045, S: 0.03 | Properties Excellent: weldability, temperature resistance (and keeps its toughness) Good: work hardening rate, corrosion resistance Fair: ductility | Applications Cold-working, screen mesh applications, wire rope, cryogenic applications, stamping |
Grade 303 | Composition % Cr: 18, Ni: 9, S: 0.15–0.35, Cu: 1 | Properties Good: ductility, temperature resistance Fair: corrosion resistance, work hardening rate Very poor: weldability, magnetism | Applications Cold-work hardening, aircraft parts, bushings, shafts, fasteners |
Grade 303Se | Composition % C: 0.15, Mn: 2, Si: 1, Cr: 17–19, Ni: 8–10, Se: 0.15, S: 0.06, P: 0.2 | Properties Same as 303 | Applications Same as 303 |
Grade 304 | Composition % Cr: 17.5–19.5, Ni: 8–10.5, C: 0.07, Mn: 2, Si: 1, P: 0.045, S: 0.015 | Properties Excellent: temperature resistance, weldability Good: corrosion resistance, ductility Fair: work hardening rate | Applications Cold-work hardening, high-pressure flanges, pressure vessels, pumps, parts found in petrochemical processing plants |
Grade 304H | Composition % C: 0.04–0.08, Mn: 2, Cr: 17.5–19.5, Ni: 8–11, Si: 1, P: 0.035, S: 0.015, N: 0.1 | Properties Excellent: temperature resistance (and it keeps its toughness), weldability Good: work hardening rate, corrosion resistance Fair: ductility | Applications Cold-work hardening, pressure vessels, pumps, boilers, condensers, heat exchangers |
Grade 304L | Composition % C: 0.03, Mn: 2, Cr: 17.5–20, Ni: 8–12, Si: 1, P: 0.035, S: 0.015, N: 0.11 | Properties Excellent: temperature resistance (and it keeps its toughness), weldability Good: work hardening rate, corrosion resistance Fair: ductility | Applications Cold-work hardening, pressure vessels, parts for mining, medical, nuclear power generation |
Grade 304N | Composition % C: 0.06, Mn: 2, Si: 1, Cr: 18–20, Ni: 8–11, P: 0.045, S: 0.015, N: 0.12–0.22 | Properties Excellent: weldability Good: corrosion resistance, temperature resistance, ductility Fair: work hardening rate | Applications Cold-work hardening, vacuum testing chambers, decarburization columns, containers that hold liquid natural gas |
Grade S30430 | Composition % C: 0.04, Mn: 2, Fe: 63.9–72, Cr: 17–19, Ni: 8.5–10.5, Cu: 3–4 | Properties Excellent: weldability Good: corrosion and temperature resistance, ductility Fair: work hardening rate | Applications Cold-work hardening, many kinds of screws, like self-tapping, light machine, sets, fasteners, bolts, rivet |
Grade 305 | Composition % C: 0.06, Mn: 2, Si: 1, Cr: 17–19, Ni: 11–13, P: 0.045, S: 0.015, N: 0.11 | Properties Excellent: ductility Good: corrosion resistance, temperature resistance Poor: work hardening rate, weldability | Applications Cold-working, acid production machinery, food and beverage equipment, deep-drawn components |
Grade 308 | Composition % C: 0.08, Mn: 2, Si: 1, Cr: 19–21, Ni: 10–12, P: 0.045, S: 0.015, N: 0.11 | Properties Excellent: temperature resistance—retaining its toughness, weldability Good: corrosion resistance, ductility Fair: work hardening rate | Applications Cold-work hardening, weldable parts, filler material in welding |
Grade 309 | Composition % C: 0.2, Mn: 2, Si: 1.5–2.5, Cr: 19–21, Ni: 11–13, P: 0.045, S: 0.015, N: 0.11 | Properties Excellent: temperature resistance without losing its toughness Good: corrosion resistance, ductility Fair: work hardening rate, weldability | Applications Cold-work hardening, incinerators, kilns, coal burners, fluidized bed furnaces, paper mill equipment |
Grade 310 | Composition % C: 0.25, Mn: 0.2, Si: 1.5, Cr: 24–26, Ni: 19–22, P: 0.045, S: 0.03 | Properties Excellent: temperature resistance while keeping its toughness Good: corrosion resistance, ductility Fair: work hardening rate, weldability | Applications Cold-work hardening, furnaces, cryogenic components, burner grids, feeders |
Grade 314 | Composition % C: 0.2, Mn: 2, Si: 1.5–2.5, Cr: 24–26, Ni: 19–22, P: 0.045, S: 0.015, N: 0.11 | Properties Excellent: temperature resistance (keeps its toughness) Good: weldability, corrosion resistance, ductility Fair: work hardening rate | Applications Cold-work hardening, heat exchangers, furnace conveyors, high-heat applications |
Grade 316 | Composition % C: 0.07, Mn: 2, Si: 1, Mb: 2–2.5, Cr: 16.5–18.5, Ni: 10–13, P: 0.045, S: 0.015, N: 0.11 | Properties Good: Work hardening rate, corrosion resistance, temperature resistance, ductility, weldability | Applications Cold-work hardening (but not with heat treatment), cookware, license plates, boat fittings, offshore structures, surgical instruments |
Grade 316F | Composition % C: 0.08, Mn: 2, Si: 1, Mb: 1.75–2.5, Cr: 16–18, Ni: 10–14, P: 0.2, S: 0.1 | Properties Fair: work hardening rate Good: corrosion resistance at hotter temperatures, ductility, temperature resistance, weldability | Applications Cold-work hardening (but not with heat treatment), surgical implants, rubber processing plants, pulp and paper industry uses |
Grade 316H | Composition % C: 0.04–0.08, B: 0.0015–0.005, Mn: 2, Si: 1, Mb: 2–2.5, Cr: 16.5–18.5, Ni: 10–13, P: 0.035, S: 0.015, N: 0.11 | Properties Good: corrosion resistance at hotter temperatures, ductility, weldability Excellent: temperature resistance Fair: work hardening rate | Applications Cold-work hardening (but not with heat treatment), power generation, wastewater treatment plants, medical equipment, parts for the pulp and paper industry |
Grade 316L | Composition % C: 0.03, Mn: 2, Si: 1, Mb: 2–3, Cr: 16.5–19, Ni: 10–15, P: 0.045, S: 0.015, N: 0.11 | Properties Excellent: temperature resistance Good: corrosion resistance at hotter temperatures, ductility, weldability Fair: work hardening rate | Applications Cold-work hardening (but not with heat treatment), parts for marine environments, textile production, chemical processing, petroleum refining |
Grade 316Ti | Composition % C: 0.08, Ti: 0.7, Mn: 2, Si: 1, Mb: 2–2.5, Cr: 16.5–18.5, Ni: 10.5–13.5, P: 0.045, S: 0.015 | Properties Excellent: strength at high temperatures Good: work hardening rate, corrosion resistance at high temperatures, ductility, weldability | Applications Products that require resistance to pitting and corrosion |
Grade 317 | Composition % C: 0.08, Mn: 2, Si: 1, Mb: 3–4, Cr: 18–20, Ni: 11–15, P: 0.045, S: 0.03, N: 0.11 | Properties Good: corrosion resistance, work hardening rate, ductility, temperature resistance, weldability | Applications Cold-working, heat-treatment, components that’ll be near or holding oil, gasses, chemicals, food, beverages, paper pulp |
Grade 317L | Composition % C: 0.03, Mn: 2, Si: 1, Mb: 3–4, Cr: 17.5–19.5, Ni: 13–17, P: 0.045, S: 0.03, Nitrogen: 0.11 | Properties Good: corrosion resistance (even at elevated temperatures), ductility, temperature resistance, weldability Fair: work hardening rate | Applications Cold-working, petroleum refining, explosives, pulp and paper processing |
Grade 317L | Composition % C: 0.03, Mn: 2, Si: 1, Mb: 3–4, Cr: 17.5–19.5, Ni: 13–17, P: 0.045, S: 0.03, Nitrogen: 0.11 | Properties Good: corrosion resistance (even at elevated temperatures), ductility, temperature resistance, weldability Fair: work hardening rate | Applications Cold-working, petroleum refining, explosives, pulp and paper processing |
Grade 317LMN | Composition % C: 0.03, Mn: 2, Si: 1, Mb: 4–5, Cr: 16.5–18.5, Ni: 12.5–14.5, P: 0.045, S: 0.015, N: 0.12–0.22 | Properties Excellent: corrosion resistance (even at hot temperatures) Good: ductility, weldability Fair: strength, hardening rate | Applications Pharmaceutical equipment, air pollution components, food and beverage processing parts |
Grade 321 | Composition % C: 0.08, Mn: 2, Ti: 0.7, Si: 1, Cr: 17–19, Ni: 9–12, P: 0.045, S: 0.015 | Properties Good: corrosion resistance at high temperatures, ductility, weldability, strength at high temperatures | Applications Work-hardening, manifolds for aircraft piston engines, food processors, expansion joints |
Grade 347 | Composition % C: 0.08, Mn: 2, Nb: 1, Si: 1, Cr: 17–19, Ni: 9–12, P: 0.045, S: 0.015 | Properties Good: work hardening rate, ductility, temperature resistance, weldability Fair: corrosion resistance | Applications Cold-work hardening, kitchen utensils, chemical processing equipment, heat exchangers, catalytic cracking units |
Grade 348 | Composition % C: 0.08, Mn: 2, Nb: 0.8, Ta: 0.1, Si: 1, Cr: 17–19, Ni: 9–13, P: 0.045, S: 0.03 | Properties Fair: weldability (through shielded gas methods) Good: corrosion resistance (at hot temperatures), work hardening rate, ductility, temperature resistance | Applications Cold-work hardening, lining the insides of reactors and fuel cells in nuclear reactors |
Grade 330 | Composition % C: 0.08, Mn: 2, Si: 0.75–1.5, Cr: 17–20, Ni: 34–37, P: 0.03, S: 0.03 | Properties Good: ductility, weldability, temperature resistance, work hardening rate Excellent: corrosion resistance | Applications Salt pots and waste remediation unit parts in chemical processing and thermal treatment plants |
Grade 384 | Composition % C: 0.08, Mn: 2, Si: 0.75–1.5, Cr: 17–20, Ni: 34–37, P: 0.03, S: 0.03 | Properties Good: ductility, corrosion resistance, temperature resistance Fair: weldability (with shielded gas techniques) Poor: work hardening rate | Applications Cold-work hardening, fasteners, parts made for steam turbines |
Grade 409 | Composition % C: 0.03, Ti: 0.65, Mn: 1, Si: 1, Cr: 10.5–12.5, P: 0.04, S: 0.015 | Properties Excellent: corrosion resistance at hot temperatures Good: ductility Fair: strength at hot temperatures, weldability Very poor: can’t be work hardened or hardened through heat treatments | Applications Agricultural equipment, car parts like exhaust systems, fuel filters |
Grade 410 | Composition % C: 0.08–0.15, Mn: 1.5, Si: 1, Cr: 11–13.5, Ni: 0.75, P: 0.04, S: 0.015 | Properties Good: strength at low temperatures Fair: ductility and corrosion resistance (at moderate temperatures), can be heat treated Poor: weldability Very poor: can’t be work hardened | Applications Wide range of applications, like scissors and more specialized component for petroleum refinery plants |
Grade 420 | Composition % C: 0.15–0.42, Mn: 1–1.5, Si: 1, Cr: 12–14, P: 0.04, S: 0.015 | Properties Good: strength in cold temperatures Fair: thermal treating, corrosion resistance, ductility Poor: weldability Very poor: can’t be work-hardened | Applications Needle valves, knives, hand tools, wear plates |
Grade 430 | Composition % C: 0.08, Mn: 1, Si: 1, Cr: 16–18, P: 0.04, S: 0.015 | Properties Good: ductility Fair: corrosion resistance and strength at hot temperatures, weldability Poor: work hardening rate and can’t be hardened with heat treatments | Applications Chimney liners, dishwasher parts, lashing wires |
Grade 434 | Composition % C: 0.08, Mb: 0.9–1.4, Mn: 1, Si: 1, Cr: 16–18, P: 0.04, S: 0.015 | Properties Good: corrosion resistance and strength at hot temperatures Fair: ductility, weldability Poor: work hardening rate and be hardened with thermal treatment | Applications Furnace combustion chambers, vehicle trim, medical equipment |
Grade 440C | Composition % C: 0.95–1.2, Mb: 0.4–0.8, Mn: 1, Si: 1, Cr: 16–18, P: 0.04, S: 0.03 | Properties Excellent: strength at cold temperatures Poor: ductility, corrosion resistance, weldability | Applications Heat hardenable (but not work hardening), knives, chisels, valve seats, roller element bearings |
Grade 904L | Composition % C: 0.02, Cu: 1.2–2, Mb: 4–5, Mn: 2, Ni: 24–26, Si: 0.7, Cr: 19–21, P: 0.03, S: 0.01, N: 0.15 | Properties Excellent: Work hardening rate Good: corrosion resistance, temperature resistance, ductility, weldability | Applications Containers for acids, components in chemical processing plants, pulp and paper mills (for bleaching), parts for brackish water processing plants |
Stainless Steel Grades
Below you can see another picture of machined parts made of stainless steel parts that we’ve made here at Xometry.
| Standard | Example | Notes |
|---|---|---|
Standard European Standard (EN) | Example 1.4301 | Notes Stainless steel names are identified numerically by 1.4 and then have three digits after that share the composition |
Standard Japanese International Standard (JIS) | Example SUS304 | Notes Japan uses the AISI standard but adds the SUS prefix |
Standard British Standard (BS) | Example BS 970 | Notes Britain has adopted the AISI standard as well |
Standard Chinese National Standard (GB) | Example — | Notes It all depends on where the steel comes from and what its composition is |
Standard German Standard (DIN) | Example DIN X12CrNi17-7 | Notes It’s governed by DIN17006 and the name will have an X, then the content of the alloying elements that make up more than 5% |
Standard International Organization for Standardization (ISO) | Example ISO15510 | Notes ISO has adopted Germany’s DIN standard. |
International Equivalents
How Xometry Can Help
Stainless steels are one of the most popular materials we help our clients with at Xometry, too. You can get a free quote from us on tons of different services, including stainless steel 3D printing, stainless steel CNC machining, and stainless steel laser cutting.
Disclaimer
The content appearing on this webpage is for informational purposes only. Xometry makes no representation or warranty of any kind, be it expressed or implied, as to the accuracy, completeness, or validity of the information. Any performance parameters, geometric tolerances, specific design features, quality and types of materials, or processes should not be inferred to represent what will be delivered by third-party suppliers or manufacturers through Xometry’s network. Buyers seeking quotes for parts are responsible for defining the specific requirements for those parts. Please refer to our terms and conditions for more information.