Why Stainless Steel

Why Stainless Steel

Stainless is all we do.

Stainless-steel has been proven time and time again to be the best performing material to use when sanitation is priority one. Heat resistant, durable, long-lasting, and sustainable, stainless-steel has the remarkable ability to retain its strength through even the most rigorous fabrication process. Beyond these practical features, its aesthetics make it a popular choice for a wide range of products and equipment.

And since Kusel services the following industries, stainless-steel’s versatility is another one of its critical benefits:

  • Commercial Kitchens
  • Cheese Plant Operators
  • Breweries
  • Cottage Cheese Makers
  • Test Kitchens
  • University Staffs
  • Bottling Plants
  • Pet Food Manufacturing Facilities
  • Wineries
  • Distilleries
  • Research & Development
  • Bakeries
  • Food Processing Plants
  • Pharmaceutical Manufacturing Facilities
  • Plumbing
  • Engineering
  • Architectural
  • Construction


WHAT IS STAINLESS STEEL, AND WHAT MAKES IT “STAINLESS”?

Stainless steel is an alloy – a combination of different metals – containing chromium, iron, manganese, silicon, carbon, and in many cases, significant amounts of nickel and molybdenum. Despite its composition containing this mix of elements, the metal that defines stainless is chromium, as all stainless steel contains at least 10.5% of it. Chromium is what makes stainless steel resistant to tarnish, corrosion, and rust – it's why it's called "stainless."

The chromium in stainless steel chemically reacts with oxygen and moisture, resulting in a process called passivation, which instantly forms a thin, protective layer of chromium oxide on the surface of the metal. While this layer is only a few molecules thick, it is inert, so it's resistant to further chemical reaction, and it's dense enough to prevent oxygen from getting through and into the underlying metal. The prevention of oxygen getting into the underlying metal is what prevents corrosion and tarnishing.

The more chromium contained in the alloy, the more resistant it is to corrosion. Some types of stainless steel also contain another chemical element called molybdenum, which increases resistance to more corrosive materials such as acid and chloride solutions. There is a wide range of stainless-steel grades available today that contain different combinations of chromium, molybdenum, and other metals. Each of these grades is designed for resistance to a variety of corrosive environments. 

The grade of stainless steel you use will be determined by the environment where it's to be used, and the liquids, chemicals, and other materials with which it will come into contact. Kusel's products are made from one of the two most common grades: Type 304 and Type 316L.

TYPE 304

  • The most common grade
  • Contains 15–20% chromium, 2–10.5% nickel
  • Relatively malleable
  • Used for home and industrial applications, including utensils, food handling, food processing equipment, and machinery parts

TYPE 316L

  • Second-most common grade
  • Contains 16–18% chromium, 10–12% nickel, 2–3% molybdenum
  • Increased corrosion resistance over 304 in most applications
  • Used in chemical and petrochemical industries, pharmaceutical equipment, medical devices, wastewater treatment, and marine applications

Corrosion compatibility charts are commonly available. These charts grade how well specific grades of stainless steel resist corrosion for hundreds of different chemicals and other materials, generally rating them with letter grades.

  • A: Excellent corrosion resistance
  • B: Good corrosion resistance; may show slight corrosion or discoloration
  • C: Fair to poor corrosion resistance; not recommended
  • D: Extremely poor corrosion resistance; not recommended for ANY use


THE DIFFERENCES BETWEEN TYPE 304 & TYPE 316L STAINLESS STEEL 

TYPE 304 STAINLESS STEEL
Type 304, with its chromium-nickel content and low carbon, is the most versatile and widely used of the austenitic stainless steels. Type 304 alloys are all modifications of the 18% chromium, 8% nickel austenitic alloy. Applications for this group of alloys are varied, and all possess somewhat similar characteristics in resistance to oxidation, corrosion, and durability. All provide ease of fabrication and cleaning, prevention of product contamination, and offer a variety of finishes and appearances.

GENERAL PROPERTIES – TYPE 304
Type 304 stainless steels can meet a wide variety of physical requirements, making them excellent materials for applications including auto molding and trim, wheel covers, kitchen equipment, hose clamps, springs, truck bodies, exhaust manifolds, stainless flatware, storage tanks, pressure vessels, and piping.

TYPICAL ANALYSIS – TYPE 304
Represented by ASTM-A240 AND ASME SA240.

Elements by Percentage by Weight – Maximum Unless Range is Specified.

C = .08 / Mn = 2.00 / P = .045 / S = .030 / Si = 1.00 / Cr = 18.00 – 20.00 / Ni = 8.00-12.00 / N = .10

RESISTANCE TO CORROSION – TYPE 304
The 18% chromium, 8% nickel alloys provide good resistance to moderately acidic or caustic solutions. Type 304 may be considered to perform similarly in most non-severe applications.

MECHANICAL PROPERTIES OF TYPE 304 AT ROOM TEMPERATURE
Typical Mechanical Properties required for annealed material covered by ASTM A240.

Yield Strength .2% offset = 30,000 / Ultimate Tensile Strength = 80,000 / Elongation = 50%. Hardness R = 90 max.

TYPE 316L STAINLESS STEEL
Type 316L is an austenitic chromium-nickel stainless and heat-resisting steel with superior corrosion resistance as compared to other chromium-nickel steels when exposed to many types of chemical corrodents such as seawater and brine solutions.

GENERAL PROPERTIES – TYPE 316L
Type 316L alloy is a molybdenum bearing stainless steel. It has a greater resistance to chemical attack than the 304 family. Similarly, Type 316L is durable, easy-to-fabricate, clean, weld, and finish.

TYPICAL ANALYSIS – TYPE 316L
Represented by ASTM-A240 and ASME SA240.

C = .08 / Mn = 2.00 / P = .04 / S = .03 / Si = 1.00 / Cr = 16.00 – 18.00 / Ni = 10.00 – 14.00 / Mo = 2.00 – 3.00

RESISTANCE TO CORROSION – TYPE 316L
The addition of 2% molybdenum makes 316L considerably more resistant to corrosion and oxidation than the 304 family of alloys.

MECHANICAL PROPERTIES OF TYPE 316L AT ROOM TEMPERATURE
Typical Mechanical Properties required for annealed material covered by ASTM-A240. Yield Strength .2% offset = 30,000 / Ultimate Tensile Strength = 80,000 / Elongation = 50%. Hardness R = 90 max.

Type 316L is considerably more resistant to solutions of sulfuric acid, chlorides, bromides, iodides, and fatty acids at high temperatures. In the manufacturing of certain pharmaceuticals, stainless steels containing molybdenum are required in order to avoid excessive metallic contamination.

While Kusel Equipment Co. provides this information, it is intended to be merely supplemental in nature. When purchasing Kusel products, it is the sole responsibility of the purchaser, their project-design, installation, and/or application teams to confirm the best use and intended purpose of Kusel products.

  • 316l Stainless Steel Chemical Compatibility

    While Kusel Equipment Co. provides this information, it is intended to be merely supplemental in nature. When purchasing Kusel products, it is the sole responsibility of the purchaser, their project-design, installation, and/or application teams to confirm the best use and intended purpose of Kusel products.

    Download Brochure
  • 304 Stainless Steel Corrosion Compatibility Chart

    While Kusel Equipment Co. provides this information, it is intended to be merely supplemental in nature. When purchasing Kusel products, it is the sole responsibility of the purchaser, their project-design, installation, and/or application teams to confirm the best use and intended purpose of Kusel products.

    Download Brochure
  • Why Kusel?

    Why Kusel?

    WELDING MAKES THE DIFFERENCE.

    Our manufacturing process includes welders that have an average of 20 years of experience, not only welding but working within both of our product lines.

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  • Why Kusel?

    Why Kusel?

    STAINLESS STEEL IS ALL WE DO

    Stainless steel is our material of choice. Whether its 304 or 316L, stainless has been proven time and time again to be the best performing material to use in the cheese-making process or when sanitation is priority one.

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  • Why Kusel?

    Why Kusel?

    DELIVERY WHEN YOU NEED IT

    We have some of the best lead times in the industry, and you can rest assured your order will be on site at the time we’ve committed to.

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