Stainless Steel Grades & Details
Midway Metals’ stainless steel products are used across the world. Available in a wide range of grades and finishes to suit a multitude of purposes, they are precision engineered to any type, length and diameter. Find a specific category of product in our Stainless Steel Catalogue. If you need support to find the right grade for your project, talk to a member of our customer service team.
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Austenitic
Austenitic stainless steel is a non-magnetic steel made using high quantities of nickel and chromium. It is one of the most common stainless steels available, largely due to its excellent resistance to corrosion. Midway Metals manufactures both general service / wet corrosion and high temperature Austenitic stainless steel grades.
| Common Name | UNS # | Forms Available | C | Cr | Ni | Mo | Ti | Other | Typical Applications |
|---|---|---|---|---|---|---|---|---|---|
| 254SMO | S31254 | Sheet, Plate, Bar, Pipe & Tube | 0.02 | 20 | 18 | 6 | - | 0.2N | Used where high resistance to chloride pitting and crevice corrosion is required, e.g. Seawater heat exchangers, bleach vats and washers in the pulp and paper industry. |
| 303 | S30300 | Bars | 012 | 18 | 9 | - | - | 02 5S | Free machining steel used where extensive machining is required. Corrosion resistance and weldability inferior to 304. |
| 304 | S30400 | Sheet, Coil, Plate, Bars, Welded & Seamless Pipe & Tube | 0.05 | 18.5 | 8.5 | - | - | - | General purpose steel with good corrosion resistance for most applications. Used for architecture, food processing, domestic sinks and tubs and deep drawing applications. |
| 304L | S30403 | Sheet, Coil, Plate, Bars, Welded & Seamless Pipe & Tube | 0.025 | 18.5 | 9 | - | - | - | Chemical plant and food processing equipment, where freedom from sensitisation is required in plate. |
| 316 | S31600 | Sheet, Coil, Plate, Bars, Welded & Seamless Pipe & Tube | 0005 | 17 | 11 | 2.1 | - | - | Used where higher corrosion resistance is required, i.e. Marine equipment. Can be welded up to 3mm without subsequent heat treatment. |
| 316L | S31603 | Sheet, Coil, Plate, Bars, Welded & Seamless Pipe & Tube | 0.02 | 17 | 11 | 2.1 | - | - | A low carbon modification of 316 where heavy section weldments are required without the risk of intergranular corrosion. |
| 316Ti | S31635 | Plate, Pipe & Tube | 0.05 | 17 | 11 | 2.1 | 0.5 | - | A titanium stabilised version of 316 used where good resistance to intergranular corrosion and high temperature strength is required. |
| 317 | S31700 | Sheet, Coil & Plate | 0.07 | 19 | 13 | 3.25 | - | - | For chemical plant – has a greater corrosion resistance than 316 in certain applications, notably in contact with brines and halogen salts. Also available in a low carbon “L” grade. |
| 904L | N08904 | Sheet, Plate, Bar, Pipe & Tube | 0.02 | 20 | 25 | 4.5 | 0 | 1.5cU | High resistance to: general corrosion in e.g. Sulphuric and acetic acids; crevice corrosion; stress corrosion cracking; pitting in chloride beading solutions. Good weldability. |
Ferritic
Ferritic stainless steel tends to contain a slightly lower volume of chromium than Austenitic grades, is free from nickel and has a low carbon content. These properties make Ferritic stainless steel is very resistant to corrosion.
| Common Name | UNS # | Forms Available | C | Cr | Ni | Mo | Ti | Other | Typical Applications |
|---|---|---|---|---|---|---|---|---|---|
| 3CR12 (1.4003) | S41050 | Sheet/Plate & Pipe | 0.02 | 11.5 | 0.4 | - | - | - | Good corrosion resistance and readily weldable it provides a cost effective choice for many structural applications where mild or low alloyed steels require regular repair or replacement. |
| 409 | S40900 | Sheet & Coil | 0.02 | 11.5 | - | - | 0.25 | - | Heat resistant steel, easily formed and welded. Mainly used for automotive exhausts or welded applications where superior performance to galvanised steel is required. |
| 430 | S43000 | Sheet, Coil, Plate & Bars | 0.6 | 17 | - | - | - | - | Interior architectural component, stove and automotive trim. Welds tend to be brittle. |
| 444 | S44400 | Sheet & Coil | 0.2 | 18.5 | - | 2 | 0.4 | - | Heat exchanger and hot water tanks and in chloride containing waters. Not prone to chloride stress corrosion – superior resistance to pitting, crevice and intergranular corrosion. Possesses excellent deep drawing properties. |
| 446 | S44600 | Tube & Pipe | 0.8 | 26 | - | - | - | - | Used for severe heat resistant applications up to 1200°C. In recuperators, highly resistant to sulphidation and oil ash corrosion. |
Martensitic
Martensitic stainless steel has an even lower chromium content than Ferritic stainless steel. It also tends to have a fairly low carbon content, but it occasionally has nickel added. Typically used to make things like cutlery and some tools, it can be hardened by heat treating.
| Common Name | UNS # | Forms Available | C | Cr | Ni | Mo | Ti | Other | Typical Applications |
|---|---|---|---|---|---|---|---|---|---|
| 410 | S41000 | Bars | 0.1 | 12.5 | - | - | - | - | General purpose grade for use in mildly corrosive environments. |
| 416 | S41600 | Bars | 0.1 | 12.5 | - | - | - | 0.20S | Free machining variation of 410. |
| 420 | S42000 | Bars | 0.25 | 12.5 | - | - | - | - | General engineering uses, such as pump and valve shafts. |
| 420C | - | Sheet, Coil, Plate & Bars | 0.3 | 12.5 | - | - | - | - | Developed for high hardness after heat treatment. Used for cutting tools, surgical knives, etc. |
| 431 | S43100 | Bars | 0.18 | 16 | 2 | - | - | - | Hardenable steel with corrosion resistance approaching 302. Used for pump shafts etc. Should be double tempered after hardening. |
| 440C | S44004 | Bars | 4.1 | 17 | - | 0.4 | - | - | Capable of being hardened to 60 Rc. Highest hardness and abrasion resistance of all the stainless steels. Corrosion resistance similar to 410. |
Duplex
Duplex stainless steel is a combination steel. An even mix of Austenitic and Ferritic stainless steel, it has a relatively high content of chromium and a low nickel content. Duplex steel grades also contain a small amount of copper (up to 3%). A combination steel, it is strong and corrosion-resistant.
| Common Name | UNS # | Forms Available | C | Cr | Ni | Mo | Ti | Other | Typical Applications |
|---|---|---|---|---|---|---|---|---|---|
| 2101 | S32101 | Sheet, Plate, Bar, Tube, Pile | 0.03 | 21 | 1.5 | 0.3 | - | 0.22N 5Mn | Low alloyed, general purpose duplex stainless steel. Its high mechanical strength is similar to that of other duplex grades and its good corrosion resistance is on par with that of most standard grades of stainless steel. Building and construction, storage tanks, flood gates. |
| 2205 | S31803 | Plate, Pipe, Bar, Fitting | 0.03 | 22 | 5.5 | 3 | - | 0.14N | Superior corrosion resistance to 316L and 317L, combined with high strength. Excellent stress corrosion and abrasion resistance. Typically used in heat exchangers, gas scrubbers, fans, chemical tanks, flowlines, marine and refinery applications. |
| 2304 | S32304 | Sheet, Plate, Pipe & Fittings | 0.03 | 23 | 4 | - | - | 0.1N | Similar corrosion resistance to 316L. Higher yield strength, corrosion and stress corrosion cracking resistance. Used where high corrosion resistance is required in marine, mining, chemical, food and power industries. Particularly useful in nitric acid. |
| 2507 | S32750 | Plate, Pipe, Bar, Fittings | 0.03 | 25 | 7 | 4 | - | 0.3N | Extremely high resistance to corrosion in severe marine, chloride and acid environments. Suitable for heat exchangers, reactors, pipework etc. |
Austenitic
Austenitic stainless steel is a non-magnetic steel made using high quantities of nickel and chromium. It is one of the most common stainless steels available, largely due to its excellent resistance to corrosion. Midway Metals manufactures both general service / wet corrosion and high temperature Austenitic stainless steel grades.
| 254SMO | |
|---|---|
| UNS # | S31254 |
| Forms Available | Sheet, Plate, Bar, Pipe & Tube |
| C | 0.02 |
| Cr | 20 |
| Ni | 18 |
| Mo | 6 |
| Ti | - |
| Other | 0.2N |
| Typical Applications | Used where high resistance to chloride pitting and crevice corrosion is required, e.g. Seawater heat exchangers, bleach vats and washers in the pulp and paper industry. |
| 303 | |
|---|---|
| UNS # | S30300 |
| Forms Available | Bars |
| C | 012 |
| Cr | 18 |
| Ni | 9 |
| Mo | - |
| Ti | - |
| Other | 02 5S |
| Typical Applications | Free machining steel used where extensive machining is required. Corrosion resistance and weldability inferior to 304. |
| 304 | |
|---|---|
| UNS # | S30400 |
| Forms Available | Sheet, Coil, Plate, Bars, Welded & Seamless Pipe & Tube |
| C | 0.05 |
| Cr | 18.5 |
| Ni | 8.5 |
| Mo | - |
| Ti | - |
| Other | - |
| Typical Applications | General purpose steel with good corrosion resistance for most applications. Used for architecture, food processing, domestic sinks and tubs and deep drawing applications. |
| 304L | |
|---|---|
| UNS # | S30403 |
| Forms Available | Sheet, Coil, Plate, Bars, Welded & Seamless Pipe & Tube |
| C | 0.025 |
| Cr | 18.5 |
| Ni | 9 |
| Mo | - |
| Ti | - |
| Other | - |
| Typical Applications | Chemical plant and food processing equipment, where freedom from sensitisation is required in plate. |
| 316 | |
|---|---|
| UNS # | S31600 |
| Forms Available | Sheet, Coil, Plate, Bars, Welded & Seamless Pipe & Tube |
| C | 0005 |
| Cr | 17 |
| Ni | 11 |
| Mo | 2.1 |
| Ti | - |
| Other | - |
| Typical Applications | Used where higher corrosion resistance is required, i.e. Marine equipment. Can be welded up to 3mm without subsequent heat treatment. |
| 316L | |
|---|---|
| UNS # | S31603 |
| Forms Available | Sheet, Coil, Plate, Bars, Welded & Seamless Pipe & Tube |
| C | 0.02 |
| Cr | 17 |
| Ni | 11 |
| Mo | 2.1 |
| Ti | - |
| Other | - |
| Typical Applications | A low carbon modification of 316 where heavy section weldments are required without the risk of intergranular corrosion. |
| 316Ti | |
|---|---|
| UNS # | S31635 |
| Forms Available | Plate, Pipe & Tube |
| C | 0.05 |
| Cr | 17 |
| Ni | 11 |
| Mo | 2.1 |
| Ti | 0.5 |
| Other | - |
| Typical Applications | A titanium stabilised version of 316 used where good resistance to intergranular corrosion and high temperature strength is required. |
| 317 | |
|---|---|
| UNS # | S31700 |
| Forms Available | Sheet, Coil & Plate |
| C | 0.07 |
| Cr | 19 |
| Ni | 13 |
| Mo | 3.25 |
| Ti | - |
| Other | - |
| Typical Applications | For chemical plant – has a greater corrosion resistance than 316 in certain applications, notably in contact with brines and halogen salts. Also available in a low carbon “L” grade. |
| 904L | |
|---|---|
| UNS # | N08904 |
| Forms Available | Sheet, Plate, Bar, Pipe & Tube |
| C | 0.02 |
| Cr | 20 |
| Ni | 25 |
| Mo | 4.5 |
| Ti | 0 |
| Other | 1.5cU |
| Typical Applications | High resistance to: general corrosion in e.g. Sulphuric and acetic acids; crevice corrosion; stress corrosion cracking; pitting in chloride beading solutions. Good weldability. |
Ferritic
Ferritic stainless steel tends to contain a slightly lower volume of chromium than Austenitic grades, is free from nickel and has a low carbon content. These properties make Ferritic stainless steel is very resistant to corrosion.
| 3CR12 (1.4003) | |
|---|---|
| UNS # | S41050 |
| Forms Available | Sheet/Plate & Pipe |
| C | 0.02 |
| Cr | 11.5 |
| Ni | 0.4 |
| Mo | - |
| Ti | - |
| Other | - |
| Typical Applications | Good corrosion resistance and readily weldable it provides a cost effective choice for many structural applications where mild or low alloyed steels require regular repair or replacement. |
| 409 | |
|---|---|
| UNS # | S40900 |
| Forms Available | Sheet & Coil |
| C | 0.02 |
| Cr | 11.5 |
| Ni | - |
| Mo | - |
| Ti | 0.25 |
| Other | - |
| Typical Applications | Heat resistant steel, easily formed and welded. Mainly used for automotive exhausts or welded applications where superior performance to galvanised steel is required. |
| 430 | |
|---|---|
| UNS # | S43000 |
| Forms Available | Sheet, Coil, Plate & Bars |
| C | 0.6 |
| Cr | 17 |
| Ni | - |
| Mo | - |
| Ti | - |
| Other | - |
| Typical Applications | Interior architectural component, stove and automotive trim. Welds tend to be brittle. |
| 444 | |
|---|---|
| UNS # | S44400 |
| Forms Available | Sheet & Coil |
| C | 0.2 |
| Cr | 18.5 |
| Ni | - |
| Mo | 2 |
| Ti | 0.4 |
| Other | - |
| Typical Applications | Heat exchanger and hot water tanks and in chloride containing waters. Not prone to chloride stress corrosion – superior resistance to pitting, crevice and intergranular corrosion. Possesses excellent deep drawing properties. |
| 446 | |
|---|---|
| UNS # | S44600 |
| Forms Available | Tube & Pipe |
| C | 0.8 |
| Cr | 26 |
| Ni | - |
| Mo | - |
| Ti | - |
| Other | - |
| Typical Applications | Used for severe heat resistant applications up to 1200°C. In recuperators, highly resistant to sulphidation and oil ash corrosion. |
Martensitic
Martensitic stainless steel has an even lower chromium content than Ferritic stainless steel. It also tends to have a fairly low carbon content, but it occasionally has nickel added. Typically used to make things like cutlery and some tools, it can be hardened by heat treating.
| 410 | |
|---|---|
| UNS # | S41000 |
| Forms Available | Bars |
| C | 0.1 |
| Cr | 12.5 |
| Ni | - |
| Mo | - |
| Ti | - |
| Other | - |
| Typical Applications | General purpose grade for use in mildly corrosive environments. |
| 416 | |
|---|---|
| UNS # | S41600 |
| Forms Available | Bars |
| C | 0.1 |
| Cr | 12.5 |
| Ni | - |
| Mo | - |
| Ti | - |
| Other | 0.20S |
| Typical Applications | Free machining variation of 410. |
| 420 | |
|---|---|
| UNS # | S42000 |
| Forms Available | Bars |
| C | 0.25 |
| Cr | 12.5 |
| Ni | - |
| Mo | - |
| Ti | - |
| Other | - |
| Typical Applications | General engineering uses, such as pump and valve shafts. |
| 420C | |
|---|---|
| UNS # | - |
| Forms Available | Sheet, Coil, Plate & Bars |
| C | 0.3 |
| Cr | 12.5 |
| Ni | - |
| Mo | - |
| Ti | - |
| Other | - |
| Typical Applications | Developed for high hardness after heat treatment. Used for cutting tools, surgical knives, etc. |
| 431 | |
|---|---|
| UNS # | S43100 |
| Forms Available | Bars |
| C | 0.18 |
| Cr | 16 |
| Ni | 2 |
| Mo | - |
| Ti | - |
| Other | - |
| Typical Applications | Hardenable steel with corrosion resistance approaching 302. Used for pump shafts etc. Should be double tempered after hardening. |
| 440C | |
|---|---|
| UNS # | S44004 |
| Forms Available | Bars |
| C | 4.1 |
| Cr | 17 |
| Ni | - |
| Mo | 0.4 |
| Ti | - |
| Other | - |
| Typical Applications | Capable of being hardened to 60 Rc. Highest hardness and abrasion resistance of all the stainless steels. Corrosion resistance similar to 410. |
Duplex
Duplex stainless steel is a combination steel. An even mix of Austenitic and Ferritic stainless steel, it has a relatively high content of chromium and a low nickel content. Duplex steel grades also contain a small amount of copper (up to 3%). A combination steel, it is strong and corrosion-resistant.
| 2101 | |
|---|---|
| UNS # | S32101 |
| Forms Available | Sheet, Plate, Bar, Tube, Pile |
| C | 0.03 |
| Cr | 21 |
| Ni | 1.5 |
| Mo | 0.3 |
| Ti | - |
| Other | 0.22N 5Mn |
| Typical Applications | Low alloyed, general purpose duplex stainless steel. Its high mechanical strength is similar to that of other duplex grades and its good corrosion resistance is on par with that of most standard grades of stainless steel. Building and construction, storage tanks, flood gates. |
| 2205 | |
|---|---|
| UNS # | S31803 |
| Forms Available | Plate, Pipe, Bar, Fitting |
| C | 0.03 |
| Cr | 22 |
| Ni | 5.5 |
| Mo | 3 |
| Ti | - |
| Other | 0.14N |
| Typical Applications | Superior corrosion resistance to 316L and 317L, combined with high strength. Excellent stress corrosion and abrasion resistance. Typically used in heat exchangers, gas scrubbers, fans, chemical tanks, flowlines, marine and refinery applications. |
| 2304 | |
|---|---|
| UNS # | S32304 |
| Forms Available | Sheet, Plate, Pipe & Fittings |
| C | 0.03 |
| Cr | 23 |
| Ni | 4 |
| Mo | - |
| Ti | - |
| Other | 0.1N |
| Typical Applications | Similar corrosion resistance to 316L. Higher yield strength, corrosion and stress corrosion cracking resistance. Used where high corrosion resistance is required in marine, mining, chemical, food and power industries. Particularly useful in nitric acid. |
| 2507 | |
|---|---|
| UNS # | S32750 |
| Forms Available | Plate, Pipe, Bar, Fittings |
| C | 0.03 |
| Cr | 25 |
| Ni | 7 |
| Mo | 4 |
| Ti | - |
| Other | 0.3N |
| Typical Applications | Extremely high resistance to corrosion in severe marine, chloride and acid environments. Suitable for heat exchangers, reactors, pipework etc. |
Frequently Asked Questions
What Grade of Stainless Steel Doesn’t Rust?
Due to its superior corrosion resistance and affordability, 304 stainless steel is the most popular type of stainless steel used globally. Most oxidising acids won’t cause 304 to corrode.
However, unlike 316 stainless steel, it is susceptible to corrosion from chloride solutions or from saline environments, such as the coast. Additionally, it is deficient in molybdenum, an alloy found in 316 that significantly improves corrosion resistance.
304 is a cost-effective and beneficial option for most environments, whereas 316 is best suited to places with heavy chloride exposure, especially close to the ocean.
What is the Hardest Stainless Steel Grade?
440C is the hardest and most abrasion-resistant of all stainless steel.
What is Marine Grade Stainless Steel?
Due to the presence of molybdenum in its composition, 316 is the most popular grade utilised for this application even though there is no industry standard for marine grade stainless steel.
It is the recommended steel for usage in marine conditions because of its superior resistance to pitting corrosion than the majority of other grades of steel without molybdenum.
What Grade of Stainless Steel is Magnetic?
Martensitic stainless steel grades, such as 410, 420, and 440 are magnetic. This kind of stainless steel is magnetic chiefly as a result of the significant amounts of ferrite—an alloy of iron and other elements—that it contains in its chemical makeup.
Additionally, most ferritic stainless steels are also magnetic. Examples are grades 409 and 431. The highest concentration of ferrite is seen in the chemical composition of this grade of stainless steel.
What is the Highest Grade of Stainless Steel?
18/10 stainless steel is one of the highest quality stainless steel. It is also known as the 304 grade. It is mostly present in kitchen equipment and common in industrial applications.
It is remarkable for its high tensile strength and it is also heat-resistant.