Stainless Steel

The term “Stainless” was pitched early when steels were used in cutlery applications. Now, the stainless steel is also known as “Inox” or “Inox steel”.

Basically, it’s an alloy of 10.5% Chromium and Iron. Although Iron is the main component of the alloy, Chromium helps produce a sleek layer of Chromium Oxide over the surface of the steel structure and the layer is known as “passive layer”.

This layer prevents further corrosion on the surface. The more chromium is added to the metal, the more resistance you get to oxidation and corrosion. Besides, the stainless steel contains Manganese, Silicone and a good amount of Carbon.

For enhanced formidability and few other useful properties, Molybdenum and Nickel may be added.

At FMB Trading And Engineering, these materials are likely to be treated and process by laser cutting, metal bending, metal rolling and metal fabrication methods with relations to mild steel, stainless steel and aluminium.

Applications of Stainless Steel

Inox or Stainless steel is a versatile material, which was primarily used for cutlery but soon proved its worth in different industries like chemical, automobile etc. Its adaptation was mainly because of the corrosion resistant characteristics. But nowadays, stainless steel is not being recognized for its corrosion resistance characteristic only. Other mechanical characteristics of this highly efficient material are getting recognition and they are getting into use for production of metal products to make them more durable, efficient and oxidation resistant.

That’s why newer applications of Stainless Steel is being brought to light and here are some successful attempt to use Stainless Steel in different industries.

Kitchenware and Cutlery

The most known and notable application of Stainless steel is for cookware sets and other kitchen appliances. Specially manufactured 420 and 410-grade steel is used to make the finest cutlery, especially for the knives because they keep the edges sharp for a long time. For the forks and spoons, 304-grade steel is used, mostly the ductile 18/8 ones, containing 18% Chromium and 8% Nickel.

Power Generation Industries

Stainless Steel is used in power generation industry for of its corrosion resistant characteristics at a high temperature. The low cobalt ones are adopted in nuclear plants. Ventilation shafts are made of stainless steel, which is used in emergencies to seal off power plants for years. Besides, Gas and Steam turbines are also made from stainless steel, because of their heat and corrosion resistant qualities.

Chimerical, Gas and Oil Industry

Chemical, Gas, and Oil processing industry has the most demand for stainless steel. Their valves, pumps, tanks, and pipes are made of stainless steel, especially grade 304. This particular grade of stainless steel is more robust than its ancestors. Apart from this one, other special grade steels are made for sewage plants, harbour supports, ship propellers, offshore oilrigs and desalination plants.

Architecture

Stainless steel roofing, facades, and cladding are new footprints of modern architecture. They are adopted in architecture for many reasons, mainly because of the anti-vandal characteristics and low-maintenance cost. It is a better replacement for carbon steel to extend the life cycle of any infrastructure.

Food Production

Stainless steel doesn’t make any impact on the taste of the food and they are easily cleanable. That’s why, inox is used for food production process, especially 316 for harsh environment and 304 for regular environment.

Automobile

For structure, exhaust system, and catalytic converter, the use of stainless steel is increasing exponentially in the automobile industry. Lesser environmental impact, low and longtime maintenance cost, minimum life cycle cost, etc. are the reasons why the market for stainless steel is getting bigger and bigger.

Medical

For artificial hips and other implants, clean melted stainless steel is used. Cabinets, orthopaedic beds, examination machines etc. made of standard stainless steel because they are hygienic and easy to clean. The pharmaceutical industry uses stainless steel for hoppers and pill funnels for piping solution and cream.

Types of grade of Stainless Steel

Basically, chromium and nickel are added to carbon steel and that’s how we get stainless steel for use. But other components like manganese, molybdenum, silicon, carbon, and vanadium are also mixed with it. This mixture of different elements makes up a 3 digit number that is broadly categorized into 4 grades.

200 series

The mixture of 7% manganese, 4% nickel and 17% chromium in the steel, makes 200 –series stainless steel. It has an austenitic structure, which refers to its crystalline structure. This steel weld easier compared to other steels and it becomes magnetic after heating.

Here are some most used stainless steel type form 200 series:

201 Stainless Steel

Chemical Composition of 201 Stainless Steel

Element	Quantity (%)
Iron	72
Chromium	16-18
Nickel	3.5-5.5
Manganese	5.5-7.5
Silicon	1
Nitrogen	0.25
Carbon	0.15

Physical Properties of 201 Stainless Steel

Properties	Imperial	Metric
Density	0.284 lb/in³	7.86 g/cm³
Tensile Strength	99400 psi	685 MPa
Yield Strength	42400 psi	292 MPa
Elastic Modulus	28573 ksi	197 GPa
Poisson’s Ratio	0.27-0.30	0.27-0.30

202 Stainless Steel

Chemical Composition of 202 Stainless Steel

Element	Quantity (%)
Iron	68
Chromium	17 – 19
Nickel	4 – 6
Manganese	7.5 – 10.5
Silicon	≤1
Nitrogen	≤ 0.25
Carbon	≤ 0.15
Phosphorus	≤ 0.06
Sulphur	≤ 0.03

Physical Properties of 202 Stainless Steel

Properties	Imperial	Metric
Tensile Strength	74694 psi	515 MPa
Yield Strength	39900 psi	275 MPa
Elastic Modulus	30000 ksi	207 GPa
Poisson’s Ratio	0.27-0.30	0.27-0.30

205 Stainless Steel

Chemical Composition of 205 Stainless Steel

Element	Quantity (%)
Iron	Balance
Chromium	16.5– 18
Nickel	1.0 – 1.75
Manganese	14 – 15.5
Silicon	1
Nitrogen	0.32 – 0.4
Carbon	0.12 – 0.25
Phosphorus	0.06
Sulphur	0.03

Physical Properties of 205 Stainless Steel

Properties	Imperial	Metric
Tensile Strength	115000-120000 psi	790 – 830 MPa
Yield Strength	65300 – 68900 psi	450 – 475 MPa
Elastic Modulus	28572 ksi	197 GPa
Poisson’s Ratio	0.27-0.30	0.27-0.30

300 Series

18% chromium and 8% nickel makes 300 series stainless steel, which is also known as 18-8 due to its percentage of those two elements. Like 200 series, they do not attract but if they are heated, magnetic properties are found. They are austenitic stainless steel like 200 series and the most popular grades are 304 and 316. They are mostly used in kitchenware production and chemical plants.

Here are some of the most used steel types of 300 series:

304 Stainless Steel

Chemical Composition of 304 Stainless Steel

Element	Quantity (%)
Iron	Balance
Chromium	18 – 20
Nickel	8 -12
Manganese	2
Silicon	1
Nitrogen	0.10
Carbon	0.08
Phosphorus	0.045
Sulphur	0.03

Physical Properties of 304 Stainless Steel

Properties	Imperial	Metric
Tensile Strength	115000-120000 psi	790 – 830 MPa
Yield Strength	65300 – 68900 psi	450 – 475 MPa
Elastic Modulus	27992.283 ksi	193 GPa

316 Stainless Steel

Chemical Composition of 316 Stainless Steel

Element	Quantity (%)
Iron	Balance
Chromium	16 – 18
Nickel	10 – 14
Manganese	2
Silicon	0.75
Nitrogen	0.10
Carbon	0.08
Phosphorus	0.045
Sulphur	0.03
Molybdenum	2

Physical Properties of 316 Stainless Steel

Properties	Imperial	Metric
Tensile Strength	115000-120000 psi	790 – 830 MPa
Yield Strength	65300 – 68900 psi	450 – 475 MPa
Elastic Modulus	27992.283 ksi	193 GPa
Density		7.99 g/cm³

Difference between 304 and 316 type Stainless Steel

In terms of elements, type 304 and 316 Stainless Steel is quite similar and the only difference between them in chemical composition is the quantity of different elements in each type.

Their Physical properties are also similar like their common elements. But apart from the quantity of the elements in each type, there are few other things that make them dissimilar.

1. Application: 304 and 316, both are commonly used grade of stainless steel. They are on the checklist for food and beverage industry. But only type 316 stainless steel is for marine applications.

Besides, due to its non-reactive quality, 316 is used for surgical instruments.

2. The quantity of Element: As we have mentioned earlier, the quantity of elements is the main difference between 304 and 316. But the most significant difference between them is the presence of Molybdenum. Where 2% Molybdenum is present in 316 type, 304 type lacks it completely.
3. Cost: 304 type is comparatively cheaper than 316.
4. Resistance: 304 stainless steel is oxidation resistant but 316 has superior corrosion resistance.
5. Chlorine Resistance: Type 316 is chlorine resistant where type 304 is not. So if your application has something to do with chlorine or its oxide or even in a salty environment, type 316 will last longer.

347 Stainless Steel

Chemical Composition of 347 Stainless Steel

Element	Quantity (%)
Iron	Balance
Chromium	17– 19
Nickel	9 – 12
Manganese	14 – 15.5
Silicon	0.75
Nitrogen	0.1
Carbon	0.8
Phosphorus	0.045
Sulphur	0.03
Molybdenum	0.75
Copper	0.75

Physical Properties of 347 Stainless Steel

Properties	Imperial	Metric
Tensile Strength	75000 psi	790 – 830 MPa
Yield Strength	30000 psi	450 – 475 MPa
Elastic Modulus	27992.283 ksi	193 GPa
Density	0.286 lb/in³	7.92 g/cm³

400 Series

This group of steel has 11% chromium and only 1% manganese. 400-series have a martensitic crystalline structure for high strength and weariness resistance. Besides, they are hardened by heat-treating.

Here are some most used stainless steel type form 400 series:

410 Stainless Steel

Chemical Composition of 410 Stainless Steel

Element	Quantity (%)
Iron	Balance
Chromium	11.5 – 13.5
Nickel	1
Manganese	1
Silicon	1
Nitrogen	0.1
Carbon	0.9 – 0.15
Phosphorus	0.04
Sulphur	0.03

Physical Properties of 410 Stainless Steel

Properties	Imperial	Metric
Tensile Strength	65000 psi
Yield Strength	30000 psi	450 – 475 MPa
Elastic Modulus	29007 ksi	200 GPa
Density	0.276 lb/in³	7.65 g/cm³

414 Stainless Steel

Chemical Composition of 414 Stainless Steel

Element	Quantity (%)
Iron	83.4
Chromium	12.5
Nickel	1.88
Manganese	1
Silicon	1
Carbon	0.15
Phosphorus	0.04
Sulphur	0.03

Physical Properties of 414 Stainless Steel

Properties	Imperial	Metric
Tensile Strength	260300 psi	1795 MPa
Yield Strength	146900 psi	1013 MPa
Elastic Modulus	29007 ksi	200 GPa
Density	0.282 lb/in³	7.8 g/cm³
Poisson’s ratio	0.27-0.30	0.27-0.30

436 Stainless Steel

Chemical Composition of 436 Stainless Steel

Element	Quantity (%)
Iron	81.3
Chromium	16
Manganese	1
Carbon	0.12
Phosphorus	0.04
Sulphur	0.03
Molybdenum	1

Physical Properties of 436 Stainless Steel

Properties	Imperial	Metric
Tensile Strength	78000 psi	538 MPa
Yield Strength	64000 psi	441 MPa
Elastic Modulus	29007 ksi	200 GPa
Density	0.282 lb/in³	7.8 g/cm³
Poisson’s ratio	0.27-0.30	0.27-0.30

600 Series

A600 series is both austenitic and martensitic with 17% chromium and 4-7% nickel. 601 to 619 versions are martensitic and 630 through 635 are both martensitic and semi-austenitic. The 600 series is extremely strong and used in the aircraft industry.

Here are some most used stainless steel type form 600 series:

601 Stainless Steel

Chemical Composition of 601 Stainless Steel

Element	Quantity (%)
Iron	Balance
Chromium	21 – 25
Nickel	58 – 63
Silicon	1
Carbon	0.1
Sulphur	0.015
Molybdenum	1

Physical Properties of 601 Stainless Steel

Properties	Metric
Tensile Strength	550 MPa
Yield Strength	205 MPa
Elastic Modulus	200 GPa
Density	8.1 g/cm³

630 Stainless Steel

Chemical Composition of 630 Stainless Steel

Element	Quantity (%)
Iron	Balance
Chromium	15 – 17.5
Nickel	3 – 5
Manganese	1
Silicon	1
Carbon	0.07
Phosphorus	0.04
Sulphur	0.03
Copper	3 – 5

Physical Properties of 630 Stainless Steel

Properties	Metric
Tensile Strength	1105 MPa
Yield Strength	1000 MPa
Elastic Modulus	197GPa
Density	7.75 g/cm³

Advantages of Stainless Steel

- Stain and Corrosion Resistant

- Strength-to-weight advantage

- Versatile and Attractive

- High strength duplex grade

- Recyclable

- High and Low-temperature resistance

- Ease of fabrication

- Hygienic

- Aesthetic appeal

- Impact resistant

- Long-term value

- Easily cleanable

- Eco-friendly

- Doesn’t impact taste in food

- Sustainability

Disadvantages of Stainless Steel

- Dirt is clearly visible on stainless steel

- The cost is higher than ordinary carbon steel

- Not all of them are magnetic

When to Choose Stainless Steel?

Stainless steel is a legit replacement for regular metal for a good number of reasons. You should choose stainless steel when you want your product to be corrosion, strain and rust proof. Besides, if your workplace is overheated once in a while, stainless steel is a safe bet.

For its crystalline structure, it is comparatively strong according to the volume and density. That’s why they are used for building structures. Along with its sheer strength, the longer life cycle is another reason for its usability in architecture.

They are recyclable too, which makes it eco-friendly. So if you are worried about the environment around you, use stainless steel oppose to regular metal. Besides, there are tons of good reasons to pick stainless steel over others, including it’s easily cleanable and hygienic surface with the high impact resistance quality.