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Stainless Steel Grades

Understanding The Differences Between Stainless Steel Grades

STAINLESS STEEL GRADES

When considering what type of Pedestrian Access Control Barrier you wish to purchase, it is important to fully understand every aspect of what you are purchasing. Each grade varies in several different aspects, and are suitable for different types of uses and environments, so picking the right one for you can easily get confusing. This page is devoted to helping you better understand which grade is the right fit for you.

What Exactly Is Stainless Steel?

Stainless Steels are iron-based alloys that contain at least 10.5% Chromium. The reference to stainless steel in a singular sense as if it were only one material is a common misconception, being that there are over 60 different types of stainless steel alloys. Such alloying elements include Nickel, Molybdenum, Titaniun, Copper, Sulfur, Phosphorus, Silicon, Manganese, Carbon and even Nitrogen. These are added to enhance structural properties like formability and strength, as well as increasing corrosion, oxidation, and heat resistance. These steels have been widely used for over 50 years now in many industrial, architectural, chemical, and consumer applications. The term 'Stainless' was coined ealy on for cutlery applications, however it evenually was adopted as a generic name for these steels and now covers a wide range of different types and grades. The selection of a particular "type" and "grade" of stainless steel varies depending upon corrosion, oxidation, and heat resistance, chemical composition, tensile strength, and metallurgical structure which all affect the ideal applications and environments.

GRADE	GENERAL DESCRIPTION	CHEMICAL COMPOSITION	CORROSION, OXIDATION AND HEAT RESISTANCE	TENSILE STRENGTH	METALLURIGAL STRUCTURE
SS304	SS304 is a nonmagnetic stainless steel possessing a minimum of 18% Chromium and 8% Nickel, combined with a maximum of 0.08% Carbon. It is the most versatile and most widely used stainless steel, available in a wider range of products, forms and finishes than any other. The 18% Chromium content mixed with the 8% Nickel makes it highly resistant to corrosion and oxidation. Overall, it is an excellent combination of strength and corrosion restistance, with the exception of high Chloride environments like warm coastal areas.	Sulfur: 0-0.03% Phosphorus: 0-0.04% Carbon: 0-0.08% Silicon: 0-1.0% Manganese: 0-2.0% Nickel: 8-10.5% Chromium: 18-20%	Corrosion Resistance to moderately aggressive organic acids, mild atomspheric conditions, and fresh water due to the higher Nickel composition, as well as oxidation resistance due to the high Chromium composition. It will typically withstand ordinary rusting. Oxidation Resistance in intermittent service to temperatures of 1600°F (870°C) and in continuous service to 1700°F (925°C).	Ultimate: 84100 psi (580 MPa) Yield: 41200 psi (284 MPa) at 0.2% offset	Austenitic Stainless Steel: This means it has a higher concentration of Chromium and Nickel. Excellent corrosion resistance, unusually good formability and increased strength.
SS316	SS316 is the standard Molybdenum-bearing stainless steel grade. With the addition of Molybdenum to the composition, it possesses better overall corrosion resistance when compared to SS304, making it the preferred steel for use in environments with higher levels of moisture such as coastal areas, because of its greater resistance to pitting corrosion. Overall, this steel is the ideal grade for you if corrosion resistance is vital.	Sulfur: 0-0.03% Phosphorus: 0-0.04% Carbon: 0-0.08% Silicon: 0-1% Manganese: 0-2% Molybdenum: 2-3% Nickel: 10-14% Chromium: 18-20%	Corrosion Resistance to moderately aggressive organic acids, fresh and sea water, and nearly every atmospeheric setting, especially those consisting of higher concentrations of Chloride ions due to its slightly higher Nickel and Molybdenum composition. Sometimes referred to as the "Marine Grade Stainless Steel". Oxidation Resistance in intermittent service to temperatures as high as 1600°F (870°C) and in continuous service to temperatures of 1700°F (925°C).	Ultimate: 84100 psi (580 MPa) Yield: 41200 psi (284 MPa) at 0.2% offset	Austenitic Stainless Steel: This means it has a higher concentration of Chromium and Nickel. Excellent corrosion resistance, unusually good formability and increased strength.
SS430	SS430 is a stainless steel used made for general pupose use. It is a non-hardenable plain chromium stainless steel that possesses magnetic qualities and a slightly lower Chromium content compared to other grades. It has an excellent finish quality making it resistant to most corrosion and oxidation from fresh water, however it is not resistant to pitting from high Chloride environments such as warm, coastal areas. It is commonly used in a wide variety of applications, however the most common being indoors.	Sulfur: 0-0.03% Phosphorus: 0-0.04% Carbon: 0-0.12% Nickel: 0-0.5% Manganese: 0-1% Silicon: 0-1% Chromium: 16-18%	Corrosion Resistance to fresh water, nitric and organic acids, and most ideally used in industrial atmospeheric environments. It has best corrosion resistance when in highly polished or buffed condition. In general, it has similar resistance to pitting and crevice corrosion as SS304, however it is best used for indoor applications. It is known for its very high stress corrosion cracking resistance. Oxidation Resistance in intermittent service to temperatures as high as 1600°F (870°C) and in continuous service to temperatures of 1500°F (815°C).	Ultimate: 65267 psi (450 MPa) Yield: 29733 psi (205 MPa) at 0.2% offset	Ferritic Stainless Steel: This means it is mainly composed of Chromium, with an extremely low Nickel composition (if any). It possesses slightly magnetic properties, and has moderate resistance to corrosion and oxidation.