businessIndustry Information
Stainless Steel
Stainless steel is a common and versatile metal defined by the fact that it is alloyed with a minimum of 10% chromium, a metal of high value, and other metals like nickel. Also known as corrosion resistant steel or chromium steel, stainless steel does not stain, corrode or rust easily.
Regular steel, like carbon steel, often contains smaller amounts of chromium. While regular steel does have enhanced properties of strength and hardness due to their chromium metal content, they are not as strong or as hard as stainless steel metal. Plus, stainless has the something extra that makes it less scratchable and just as strong and durable as other steel metals–stainless steel alloys develop a passivation layer of chromium oxide on their outer surface, effectively coating the steel and protecting it from the harmful oxidation that occurs between exposed iron and oxygen molecules in the air, which makes stainless steel more effective and attractive then regular steel. This protecting layer of chromium oxide easily reforms when scratched, making stainless steel an excellent, durable metal solution with no surface cracking or pores.
Applications
Manufacturers choose to use stainless steel as a metal production material because it offers levels of resistance to corrosion, durability, strength, inertness and versatility that other metal alloys cannot match.
Suppliers use stainless steel for applications in many, many industries. Among these industries are: aerospace, architecture, automotive, cookware, healthcare, military and defense, jewelry, HVAC, general manufacturing, 3D printing, and more.
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Stainless Steel – Metalmen |
Stainless Steel – Source 21, Inc. |
Stainless Steel – Source 21, Inc. |
Stainless Steel – Source 21, Inc. |
History
The first recorded observation by a metallurgist that chromium-alloyed irons do not corrode was in 1821 by the Frenchman Pierre Berthier. At that time, he recommended that alloys like these be used to make cutlery. His contemporaries were not, however, able to make stainless steel alloy as we know it today. Instead, 19th century metallurgists were only able to provide brittle, high-chromium alloys.
It was not until close to the turn of the 20th century, in 1872, that someone was able to make what we would consider modern stainless steel. About 20 years later, in Germany, a chemist named Hans Goldschmidt developed a thermite process for producing carbon-free chromium, which would later help scientists make better stainless steel. From 1904 to 1911, there was a flurry of activity from researchers that taught them how to do just that–make better stainless steel.
The first major stainless steel-esque product, a German sailing yacht was built in 1908. In 1912, Harry Brearley discovered and industrialized martensitic stainless steel while searching for a corrosion-resistant alloy steel for gun barrels. A company called Firth Vickers later patented in England, selling it under the name “Staybrite.” When Brearley applied for a stainless steel patent in the United States, he discovered it had already been patented by a man named Elwood Haynes. He then reached out to Haynes and persuaded him to join forces with him. They subsequently pooled their funding, secured a group of investors, and formed the American Stainless Steel Corporation. After this, though it took steel suppliers and the press several years to come up with a common name for it, stainless steel became an industrial staple. Today, manufacturer use sheets, bars, and shapes of all kinds to create products of all kinds.
Production Process
Manufacturing stainless steel is a 7-step process. From sheets and tube, to tri-ply cookware, it produces many different forms, products and parts.
Step 1
First, the raw materials are melted together in an electric furnace for 8 to 12 hours, until they reach their recrystallization temperature.
Step 2
The molten steel is then cast into semi-finished forms called blooms, billets, slabs, rods and tube rounds.
Step 3
The unfinished shapes then undergo hot roll forming. During hot roll forming, blooms and billets become bars, wire and coil, and slabs become plate products, tube products, strips, sheets and foil. Note: “Plate” does not refer to your traditional dinner plate (though you can get a dinner plate set made from stainless steel!). Rather, in this context, “plate” refers to a flat piece of steel that can be used to make all sorts of products, including countertops, tabletops, and even components of ships and buildings.
Step 4
The new stainless steel stock shapes are then heat treated through annealing. During annealing, the steel is heated and then cooled through quenching or air hardening. The steel hardens or softens, depending on the amount of time manufacturers let it cool.
Step 5
When it has cooled, manufacturers descale the stainless steel in order to remove any buildup by pickling or electro cleaning.
Step 6
It is then cut to obtain its final desired shape and size by shearing, blanking, nibbling or flame cutting.
Step 7
If manufacturers plan to do further processing in to acquire a certain type of finish, such as a dull or shiny one, they employ: hot rolling, cold rolling, annealing or descaling. In addition, they may employ any combinations of these processes. Manufacturers make stainless steel products from stock shapes like cold-rolled sheet, stainless steel plate, stainless steel pipe, and stainless steel tubing.
Note: Before becoming parts and components in industrial and commercial products, all stainless steel must meet specific requirements, such as toughness or corrosion resistance, put forth by the American Society for Testing and Materials (ASTM) to ensure quality and safety.
Most manufacturing is done using 3 main types of stainless steel; all combine nickel alloy, carbon and molybdenum in different ratios to achieve different qualities.
Austenitic Stainless Steel
Austenitic stainless steel combines the largest ratios of chromium, nickel and molybdenum and accounts for about 70% of fabricated stainless steel, with the most common of the grades being 18/10 stainless steel, an alloy which is very hard, durable and resistant to corrosion. Austenitic type stainless steels have a great strength-to-weight advantage over other materials; they also provide impact resistance and toughness in extreme temperatures, making them suitable for cryogenic products and applications.
Ferritic Stainless Steel
Ferritic stainless steel has very low nickel content, higher carbon content and is very corrosion resistant but less strong and durable than austenitic type stainless steel.
Martensitic Stainless Steel
Martensitic type stainless steel contains nickel, higher levels of carbon, and often molybdenum, making it extremely strong and durable with lower corrosion resistance. Some types of stainless steel can transform from a martensite to an austenitic alloy under heat treatment or with the addition of chromium. For example, maraging steel, a specialty type of low-carbon, ultra-high strength steel alloy, is transformed into martensite when a portion of the alloy's nickel content is substituted by chromium to enhance corrosion resistance and hardness.
In addition, some steels, known as duplex stainless steel, are made via a combination of austenitic and ferritic grains. Duplex type stainless steel is about twice approximately twice as strong as regular austenitic type stainless steel and regular ferritic type stainless steel.
There are 150 grades of steel alloy, which are classified in 4 different groups according to their varying corrosion resistances and mechanical properties.
200 Series
200 series stainless steels are non-magnetic and austenitic. They are the stainless steel type with the most resistance to attacks. They contain 17% chromium, 4% nickel and 7% manganese. You can use this type of metal to make a variety of stainless steel stock products, including stainless steel sheet.
300 Series
300 level series type stainless steels are almost identical to 200, except that they are a bit less attack-resistant, contain slightly more chromium, and contain 8% metal nickel. The most popular type of stainless steel alloy is one of the 300 grades, 316 Stainless Steel. This alloy type is so popular because it has the best corrosion resistance of all (due to its high nickel content).
400 Series
400 series stainless steels are magnetic and martensitic. A few 400 type stainless steels, such as stainless steel 408, contain nickel. Stainless steel alloy grades in the 400s, which contain 11% chromium and 1% manganese, have poor corrosion resistance.
600 Series
Finally, 600 series steel grades can be heat treated to very high strength levels. Thanks to this heat treatment, a type called precipitation hardening, stainless steel 600 grades are very resistant against water and chloride attack.
Products Produced
Steel service centers manufacture stainless steel metal into a variety of shapes and products, including stainless steel foil, stainless steel strip, stainless steel wire, stainless steel tube, stainless steel tubing, stainless steel plate, stainless steel bars, stainless steel pipe, stainless steel rods, stainless steel coil and stainless steel sheet.
Stainless steel is also used to make consumer goods, including domestic kitchen supplies and tableware, sinks, laundry equipment, flatware and electronic appliances. In the food and beverage industry, manufacturers use it to make silos, wire mesh strainers, vats, kegs and large kitchen equipment. In addition, stainless steel is also found in the construction and engineering industries as roofing, gutters, elevator doors, public seating, and is used to build large skyscrapers. Automotive parts, bus frames, pipes, valves, pumps and industrial mixers are also often made out of stainless steel metal. Stainless steel countertop is popular where sanitation is important. Stainless steel tube and pipe products can be very important in the creation of dishwashers, clothing washers, and water systems of all kinds.
Advantages
No matter what stainless steel product you seek, this type of metal offers users many advantages. First, it is versatile; there are stainless steel grades for every application. Remember, stainless steel is produced in over a hundred different grades, which differ depending on their alloys, strengths, temperature resistances and applications. Second, no matter the exact grade, stainless steel is, by and large, far more durable and strong than most other metals. Also, this type of metal is corrosion resistant, rust resistant, and stain resistant. Next, it easy to sterilize, meaning that it is acceptable for many food grade and medical grade applications, like plate, tube and table products. Plus, it doesn’t require special paints or finished in order to perform. This means that you save money. Finally, stainless steel is both reusable and recyclable. Since manufacturers can reuse the alloy, they can lower their costs and pass these savings onto customers. Items like tube products and plate products are particularly useful in upcycling. More important than that, when manufacturers and end-users recycle and upcycle stainless steel products, they help the environment.
Things to Consider
There are a lot of metal suppliers out there, both domestically and abroad, who will offer you stainless steel products. Many offer similar prices, lead times, and products, which is why choosing a stainless steel manufacturer can be so hard. To help you make this decision, consider the following: Do they understand your specifications and requirements? Can they create quantity of parts or products that you need? Can they produce products that meet the standards and regulations of your region and industry? Are they willing to work within your budget and timetable? Can they create custom products? Finally, most importantly, do they have your best interests in mind? It’s very important to go with a stainless steel manufacturer that truly wants to help you make your application work, or bring your vision to life, rather than simply make a profit. Look for a company that cares, and you won’t go wrong.
Overseas Supplier Market
Because stainless steel is such a universally sought-after metal material, it produced and traded both in the United States and abroad. In addition, many American companies buy and sell abroad with a contract manufacturer. Despite the difficulties faced by the steel industry over the last several years, experts predict that global consumption of this metal will only increase as time goes on. As of 2015, North America was third largest steel producer, behind Asia and Oceania, and the European Union. So, how does this global expansion of the market impact the industry here in the U.S.? Well, domestic stainless steel prices have risen, and many people now turn to imported steel for their applications.
Why should you, then, continue to shop locally? First, consider this: while the savings of international trade may be appealing, it’s important to remember that stainless steel coming from other regions is not manufactured with the same standards as the United States. In particular, countries like China do not impose as high of standards and regulations on their steel suppliers as does the U.S. So, when you import stainless steel, you risk getting an inferior stainless steel product that will fail you or will fail industry tests. In addition, there is no substitute for customer service. When you work with a local stainless steel fabricator, you are able to discuss your application and specifications at length. This is much more difficult to do if your supplier is overseas. Plus, an American company will likely be far more familiar with and committed to American industry regulations. Find a great American company with excellent turnaround times by browsing the list of suppliers we have listed near the top of this page.
Stainless Steel Types
-
is an austenitic alloy that has sulfur and/or selenium added to create
a free-machining stainless steel. 303 stainless steels take less time
to machine, resulting in longer lasting machine tool bits and lower
production cost.
-
is an austenitic alloy that is easily formed and welded but is not a
free-machining material. 304 stainless steel is commonly used for sheet
metal products that are not subject to harsh environments.
-
is one of the most frequently used austenitic alloys in the stainless
steel family. 304L stainless steel is utilized when parts are to be
welded, especially if the weld might come in contact with chlorinated
water.
-
is an austenitic alloy that is very corrosion resistant and has a higher
nickel content. 305 stainless has a decreased tendency to work-harden
during the cold heading process.
- 316 stainless steel is a non-magnetic material that contains molybdenum and a higher nickel
content. 316 stainless steel, an austenitic alloy, is very corrosion
resistant but is subject to attack if exposed to high levels of chlorine
for a long period of time.
-
is a highly corrosion resistant austenitic alloy that is second only
to 304 stainless steel in importance. 316L stainless steel is commonly
used in heavy gauge welded components, as it offers higher creep, stress-to-rupture
and tensile strength at elevated temperatures.
-
has a very high nickel content and is very corrosion resistant to chlorides.
384 stainless steel, an austenitic alloy, cold heads well.
- 420 stainless steel refers to a small group of the steel alloys with similar chemical compositions, grouped together based on the judgement of SAE International, or the Society of Automotive Engineers. Grade 420 stainless steels are high carbon steels with, at minimum, a 12% chromium content.
- Austenitic stainless steel is comprised of chromium and nickel and is used
in mild, harsh and corrosive environments. Austenitic stainless steel
alloys account for about 70% of the stainless steel family.
- ,
along with the elements iron, chromium and nickel, contain molybdenum,
nitrogen, copper and very little carbon. Duplex stainless steel has
double the strength of austenitic stainless steel and better corrosion
resistance than martensitic stainless steel.
- consists of only iron and chromium. Ferrite stainless
steel is magnetic, cannot be hardened and is used mainly in decorative
trim and mufflers for vehicles.
- have low chromium levels and
high carbon content but do not contain nickel. Martensitic stainless
steel is a magnetic material that has reduced corrosion resistance but
can be heat-treated to provide high strength and toughness characteristics.
- are chromium-nickel grades that can be strengthened
and hardened by adding such elements as copper and aluminum in an aging
treatment at elevated temperatures.
- Stainless steel alloys offer higher corrosion resistance due to their ability to develop a passivation layer of chromium oxide on their outer surface, effectively coating the steel and protecting it from the harmful oxidation that occurs between exposed iron and oxygen molecules in the air.
-
are solid pieces of various grade stainless steels that are rolled from
billets. Stainless steel bars can be hot or cold finished and formed
into rounds, squares, hexagons, octagons or flats.
- Stainless steel coil is a rolled product that is formed from stainless steel strip.
- Stainless steel foil offers increased corrosion resistance, strength and electrical resistance as compared to traditional metal foils such as aluminum and copper foil.
- Stainless steel grades are categorized into six different series: 100 series, 200 series, 300 series, 400 series, 500 series and 600 series.
-
are tubes that are used to transport gases or liquids. Stainless steel
pipes are much longer lasting than similar products consisting of other
metals, because of the corrosion resistance of the material.
-
have a width over eight inches and a thickness from one quarter of an
inch to over a foot.
- are long cylinder-shaped objects made of stainless steel.
-
are large, thin slices of stainless steel. Usually rectangular or square
shaped, stainless steel sheets offer the flexibility of being custom
fabricated or molded.
- Stainless steel suppliers provide the rods, sheets, and plates used in the assembly of many products.
- Stainless steel strip is a flat-rolled, very thin sheet of stainless steel.
-
ranges in size from less than .01 inches to more than six inches in
diameter.
-
offer good strength-to-weight ratios, as well as rustproof performance.
Common diameters of stainless steel wires range anywhere from .01 inches
to 1-1/16 inches.
Stainless Steel Grades
Material |
Tensile Strength at Break (MPa) |
Tensile Strength, Yield (MPa) |
Modulus of Elasticity (ksi) |
All Stainless Steel |
85.0 - 3000 |
46.8 - 2400 |
10000 - 46000 |
Precipitation Hardening
Stainless |
310 - 3000 |
276 - 2400 |
10000 - 33400 |
T 300 Series Stainless Steel |
250 - 2200 |
138 - 1800 |
11000 - 31000 |
T 400 Series Stainless Steel |
280 - 2030 |
165 - 1900 |
10500 - 46000 |
T 600 Series Stainless Steel |
550 - 1720 |
46.8 - 1590 |
29000 |
T S10000 Series Stainless
Steel |
848 - 2520 |
421 - 2100 |
11200 - 33400 |
T S20000 Series Stainless
Steel |
670 - 1830 |
292 - 1730 |
24800 - 30500 |
T S30000 Series Stainless
Steel |
450 - 1620 |
200 - 1480 |
27600 - 29000 |
T S40000 Series Stainless
Steel |
455 - 1800 |
207 - 1730 |
29000 - 31200 |
Grade 201 (Annealed) |
792 Min. |
310 Min. |
26600 |
Grade 202 (Annealed) |
655 Min. |
275 Min. |
28600 |
Grade 301 (Annealed) |
861 Min. |
275 Min. |
28000 |
Grade 302 (Annealed) |
655 Min. |
262 Min. |
28000 |
Grade 304 (Annealed) |
655 Min. |
262 Min. |
28000 |
Grade 304L (Annealed) |
655 Min. |
262 Min. |
28000 |
Grade 305 (Annealed) |
620 Max. |
241 Min. |
28000 |
Grade 316 (Annealed) |
689 Max. |
275 Min. |
28000 |
Grade 316L (Annealed) |
689 Min. |
206 Min. |
28000 |
Grade 321 (Annealed) |
586 Min. |
275 Min. |
28000 |
Grade 347 (Annealed) |
620 Nom. |
275 Min, |
28000 |
Grade 405 (Annealed) |
448 Min. |
275 Nom. |
29000 |
Grade 409 (Annealed) |
NA |
N/A |
29000 |
Grade 430 (Annealed) |
482 Min. |
310 Min. |
29000 |
Grade 410 6 (Annealed) |
551 Min. |
275 Min. |
29000 |
Grade 420 6 (Annealed) |
655 Nom. |
344 Nom. |
29000 |
Grade PH17-7 (Annealed) |
1034 Max. |
448 Max. |
29500 |
*These figures are
guidelines based on industry research; they should not be presumed
accurate under all circumstances and are not a substitute for certified
measurements. The information is not to be
interpreted as absolute material properties nor does it constitute a
representation or warranty for which we assume legal liability. User
shall determine suitability of the material for the intended use and
assumes all risk and liability whatsoever in connection therewith.
Stainless Steel Terms
-
A heat-treating process used on martensitic stainless steels to harden
them. The material is heated above its critical temperature, held at that
temperature to ensure uniform temperature and then quenched in air or
oil to quickly cool it.
- A solid solution of
two or more metals. All forms of stainless steel are alloys.
- A process by which
a cold-rolled steel coil is heated to a designated temperature and then
cooled. The annealing process makes the coil easier to bend and form.
-
A process with a short operation time and low temperatures that is used
to reduce the carbon content of stainless steel during the refinement
process.
- A short bar of metal.
- A piece of sheet stainless
steel that has the specified outer dimensions of a part but has not yet
been stamped by the end user. Blanks decrease the cost of labor and transportation
for the stainless steel processor.
- A cylinder lined
with heat resistant bricks that steel mills use to smelt iron from ore.
The name originates from the blast of hot air that is forced up through
the ore.
- A semi-finished form
of stainless steel that typically has a cross-section greater than 36
sq. inches. A bloom will be further processed into mill products.
- A ridge on the edge of
strip stainless steel that is caused by cutting operations, including
blanking, trimming, shearing or slitting.
- An element added
to stainless steel, resulting in a corrosion resistant alloy.
- Also called "cold
working" it is any kind of mechanical operation performed at room
temperature that causes permanent deformation. Cold forming, which includes
bending, rolling and drawing, increases the hardness and strength of stainless
steel.
- A time-saving
process of pouring stainless steel directly from the furnace into a billet,
bloom or slab. Continuous casting eliminates the need for large, expensive
mills.
- The ability of steel
to go through permanent changes of shape without fracturing.
- Coated with zinc.
Galvanizing provides more corrosion resistance and is used on auto underbody
parts, storage tanks, garbage cans, etc.
- A number or symbol given
to different varieties of steel. Different grade steels have varying characteristics
and compositions.
- Method used to
wind narrow strip steel over a wider roll. The oscillating process is
similar to winding fishing line over a spool.
- A
steel bar used to further strengthen concrete. Rebars are vital for highway
reinforcement as well as building construction.
More Stainless Steel Information
Stainless Steel Informational Video