How many grades of stainless steel are there?

Stainless steel:

Stainless steel is a combination of a few distinct sorts of metal. When these metals are combined together they become stronger and tougher than when they were isolated. By combining different components to form stainless steel, engineers have had the option to make various assortments of the compound, each with their own qualities and uses. Stainless steel is a flexible metal and can be utilized for some, various things going from development to kitchen hardware. Various kinds of stainless steel grades are utilized in food administration foundations, and each type has its own advantages and disadvantages. To settle on an educated choice when buying food grade stainless steel hardware, you ought to comprehend the significant components in the compound, the distinctive grading system, and the primary kinds of stainless steel.

Stainless Steel Grades:

Here are the different series of stainless steel which are used commonly. It contains series of 200, 300, 400, 500 and 600. Among these series the applications of 300 series are more common than the other series.

300 Series:

These are the austenitic stainless steels. The alloying elements of these series are carbon, molybdenum and nickel. In the acidic environment, the presence of molybdenum helps to improve the corrosion resistance. Whereas, the presence of nickel enhances the ductile ability of the steel.

  • Type 301:

This type of stainless steel is highly ductile. It contains very good ability of welding. During a mechanical work, it can be hardened rapidly. It also contains a good resistance and a good fatigue strength.

  • Type 302:

This type of stainless steel contains the corrosion resistance similar to type 304. The compounds in this series contain additional elements of carbon due to which it possess a higher strength.

  • Type 303:

It is considered as the easy machine version. This type of stainless steel contains the additional elements of phosphorus and sulfur. According to the ISO (International Organization for Standardization 3506) this type is referred as “A1”.

  • Type 304:

It is the most common type of stainless steel which is used in the kitchen utensils. It is considered as the 18/8 classic stainless steel. This type is referred as “A2” according to ISO (International Organization for Standardization 3506).  It contains a very high level of nickel and chromium due to which it shines very bright. This type of stainless steel also has a good resistance against the rust and corrosion.

  • Type 309:

This type of stainless steel contains the better resistance of temperature as compared to the resistance of type 304.

  • Type 316

After type 304 of steel, the most normal grade for the purpose of food combining with surgical (without any stain) steel utilizes; alloy including molybdenum restricts some particular types of corrosion. This steel is also called marine grade steel that is without any stain because of this steel’s higher resistance to corrosion of chloride contrast to 304 type of steel. Other than that, SS36 is sometimes utilized for constructing the plant of nuclear reprocessing. Majority of the watches made of steel that is stainless are basically made of this type of steel, excluding the Rolex watch. Because in manufacturing of Rolex, 904L type is used. 18 out of 10 stainless watches are composed of this type of steel.

  • Type 321:

This type is quite similar to the type 304. As it contains the additional element of titanium so the presence of this element lowers the decay risk of welding.

Series of 400:

This series of stainless steel contains martensitic and ferrite. This type is used for treating heat. It provides an excellent combination of high resistance and strength. Whereas, the corrosion properties of resistance are lower than the resistance properties of 300 series.

  • Type 408:

Type 408 contains heat that is very resistant but the corrosion resistance is a little poor containing 8% Nickel along with 11% Chromium.

  • Type 409:

Type 409 is the cheapest type of steal that is generally utilized for the exhaustion process of automobiles. This type of steal contains only iron or chromium that is ferrite.

  • Type 410:

Type 410 of steal is martensitic that means this type contains high strength of chromium or iron. Other than that it is wear resistant however corrosion resistant is comparatively less.

  • Type 416:

This type of steal is comparatively easier to utilize in light of the fact that it contains sulfur in an additional amount. 

  • Type 420:

This type of steel is martensitic that is ‘cutlery grade’ which is quite similar to that real Brearley steel that is rustles. This type of steel is also called surgical steel. Other than that, this steel contains great polish ability. 

  • Type 430:

Type 430 of steel is quite decorative. For instance, it contains trim that is automotive along with which it contain a great kind of formability but comparatively with less resistance in corrosion and reduced temperature.

  • Type 440:

This type of steel is contains a higher evaluation of cutlery steel comparatively, containing carbon in it that is of good quantity, that takes into consideration much better edge maintenance whenever this kind of steel is properly heat treated. This kind of steel tends to be solidified to hardness of 58 Rockwell that eventually makes this kind of steel most hard treated steel. Otherwise called "extremely sharp edge steel". In addition to that, it is accessible in three evaluations 440A, 440B, 440C combing with 440F.

500 series:

Stainless steel grading also contains the series of 500. But it is not very common. These series contain the heat resisting properties. Moreover, this series contains the chromium alloys.

600 series:

There also exist the 600 series which is also not very common as compared to other series of stainless steel. This series contains the precipitation properties. It is composed of Martensitic hardening alloys.

  • Type 630:

This type of stainless steel is considered as containing the most common PH. This is well known as 17-4. This type contains 4% of nickel elements and 17% of chromium elements.