An Extensive Guide To Choosing The Right Commercial Stainless Steel Equipment
If you run a business in a commercial space, you will most likely have one or more pieces of commercial stainless steel equipment in your facility, such as a stainless steel trolley or a stainless steel rack. They are low-maintenance and long-lasting pieces of equipment that many Singapore businesses cannot function without.
Depending on your company's operational needs, you may need a different type of stainless steel equipment. If you're just getting started on putting together your own commercial facility, check out our comprehensive guide to selecting the most suitable commercial stainless steel equipment.
AN INTRODUCTION TO STAINLESS STEEL
2.1. What Is Stainless Steel?
Stainless steel is a group of iron-based alloys that contain a minimum of approximately 11% chromium, this composition prevents the iron from rusting, while also providing heat resistance and other great properties. Other substances commonly included are Nickel, Carbon, Manganese, Molybdenum, Nitrogen, Sulphur, Copper and Silicon; each of these variations would cause slightly different chemical attributes that influence how the stainless steel performs.
While most stainless steels contain at least 11% chromium, its exact composition will vary depending on the grade and intended use of the material.
Stainless steel’s resistance to corrosion is due to the presence of chromium, which forms a protective film that prevents the underlying material from corrosion attack, it can even self-heal in the presence of oxygen.
Its corrosion resistance can be increased further by adding more of certain elements to the mix. They include increasing the chromium content to more than 11%, adding nickel to at least 8%, which aids in stability and strength, and adding molybdenum. On top of that, nitrogen and carbon can be added to harden and strengthen the steel, increasing mechanical strength.
Stainless steel is an ideal material for many applications due to its resistance to corrosion and staining, low maintenance, appearance, as well as durability. It can be rolled into sheets, plates, bars, wire and tubing which can be used in the production of many products. Some of these products include cookware, cutlery, surgical instruments, storage units, major appliances, construction material in large buildings and industrial equipment.
2.2. Why Is Stainless Steel Good For Commercial Use?
Stainless steel is a popular material used in commercial settings; it can be found in stainless steel shelves, stainless steel trolleys, stainless steel work tables, and a variety of other products. Due to their properties, they are often the go-to option.
Stainless steel is one of the most long-lasting, versatile, and trouble-free metals available. Aside from corrosion resistance, here are some of its other advantages:
I. High and Low-temperature Resistant
The number of stainless steel grades available in the market is countless. Due to their alloying characteristics, stainless steels have a high tolerance towards different temperatures.
II. Non-reactive Surface
Stainless steel is a non-reactive metal, which means that stainless steel work tables can be used to prepare or cook foods that are acidic like citrus fruits, tomatoes, and vinegar. Being non-reactive will also keep it safe for use.
Stainless steel is a form of alloy made up of different substances, which makes it naturally stronger than pure metals. Alloys contain atoms of varying sizes, which distorts the regular arrangement of atoms and makes it much more difficult for layers to slide over each other. Furthermore, some stainless steels can be heat treated to produce extremely strong components.
IV. Aesthetic Appeal
Stainless steels are available in many surface finishes. You can find lots of chrome-plated shelving, furniture legs, and even some with gold-plated finishes. It is also easy to maintain, which gives them a highly pleasing appearance.
V. Hygienic Properties
On top of being a material that is easy to clean and maintain, stainless steel has a non-porous surface, which means that no liquid or substance can penetrate its surface and get trapped within. Its hypoallergenic and cleanability properties make it the first choice in hospitals, kitchens, as well as food and pharmaceutical processing facilities.
VI. Life Cycle Characteristics
Due to its durability and corrosion-resistant properties, stainless steel has a longer lifespan compared to other metals. Different stainless steel grades have varying costs, however, stainless steel is generally cost-effective, which makes them a value-for-money choice in the long run. They can even be recycled.
STAINLESS STEEL GRADES AND FAMILIES
While stainless steels offer great benefits, there are other factors that can contribute to the difference in their properties. Understanding the different types of stainless steels available is essential to finding the optimal traits and price point for your needs.
Due to its versatility, durability and affordability, stainless steel production continues to develop and increase around the world year after year. One of the first steps in finding the best options when working with stainless steel is determining the proper alloy for your product.
There are two main labels you’ll find on most stainless steels; families and grades. Read on for a comprehensive guide on them.
3.1. Stainless Steel Families
Stainless steel families refer to specific properties and they give you an idea as to the ratio of various metals in the alloy. Stainless steel falls into four distinct families; austenitic, ferritic, duplex and martensitic and precipitation hardening stainless steel.
3.1.2. Austenitic Stainless Steel
The austenitic stainless steel is the largest family of stainless steels and is the most popular and widely used family around the world. They make up about two-thirds of all stainless steel production.
Austenitic stainless steels possess an austenitic microstructure, which is a face-centred cubic crystal structure. This structure is achieved by alloying steel with sufficient nickel and/or manganese and nitrogen to maintain an austenitic microstructure at all temperatures, ranging from the cryogenic region to the melting point. Aside from chromium, they often contain molybdenum as well.
While most austenitic stainless steels are non-magnetic when annealed with a solution, certain cold worked grades are magnetic. Heat-based hardening will not work with this family of stainless steels since they possess the same microstructure at all temperatures. However, austenitic stainless steels offer excellent corrosion resistance and creep resistance while remaining great for welding.
Creep resistance is a term used to describe a material’s ability to resist the tendency of slowly deforming over a long period of exposure to high levels of stress.
Due to their excellent corrosion resistance, austenitic stainless steel is heavily depended on by the food, pharmaceutical, chemical, petrochemical and pulp and paper industries. This is because they are low maintenance, prevent product contamination, and have a long lifespan.
Popular grades of austenitic stainless steel include 303, 304, 316, 310 and 321 grades.
3.1.3. Ferritic Stainless Steel
Ferritic stainless steels possess a ferrite microstructure, which is a border-centred cubic crystal structure. They contain between 10.5% and 27% chromium with very little to no nickel. Due to the chromium addition, this ferrite microstructure remains regardless of whether it is placed in a freezing temperature or in high temperatures. Heat-based hardening will not work with ferritic stainless steels as well. They also cannot be strengthened by cold work to a similar degree as austenitic stainless steels.
Due to the low nickel content, ferritic stainless steels are one of the most cost-effective families available. They are also less expensive in comparison to austenitic stainless steels. However, although they have low nickel content, ferritic stainless steels are often added with molybdenum, niobium and titanium to improve toughness and creep resistance.
Most ferritic stainless steels are magnetic and offer good corrosion resistance. They are present in many products such as automobile exhaust pipes, architectural and structural applications and building components. This family of stainless steel is most popularly used in indoor or out-of-sight applications as they are well suited for situations where visual appeal is not as important as cost and performance.
Common grades of ferritic stainless steel include 409 and 430 grades.
3.1.3. Duplex Stainless Steel
The duplex stainless steel family has a mixed microstructure of austenite and ferrite stainless steels. The ideal ratio is a 50:50 mix but some commercial alloys may have ratios of 40:60.
Duplex stainless steels typically have a higher chromium content of 19% to 32%, a molybdenum content of up to 5% and a lower nickel content compared to austenitic stainless steels. They also have about two times the yield strength of austenitic stainless steels; which refers to the maximum stress that can be applied to the steel before it begins to change shape permanently, and their mixed microstructure provides improved resistance to chloride stress corrosion.
Duplex stainless steels are achieved through a combination of lesser metals and lower alloy content, making them a cost-effective option for many applications.
One of the first industries to extensively use duplex stainless steel was the pulp and paper industry, followed by the oil and gas industry. This led to the development of other duplex stainless steel grades like the super duplex and hyper duplex grades.
Common duplex grades include 318L, LDX 2101, LDX 2304, 2507 and 4501 (Also known as 25CR super duplex) grades.
3.1.4. Martensitic and Precipitation Hardening Stainless Steel
Martensitic and precipitation hardening stainless steels are the least common of the four major stainless steel families. However, they are popular in applications requiring precise, hardened edges, such as knives, scissors, razors and medical tools. Tempering and hardening can be done to this family of stainless steels due to the addition of carbon.
Martensitic stainless steels offer a wide range of properties but are not as corrosion resistant as ferritic and austenitic stainless steels due to their low chromium content. Precipitation hardening steels, on the other hand, have corrosion-resistant properties comparable to the austenitic varieties and can be hardened to even higher strengths compared to the martensitic grades.
Common grades of martensitic and precipitation hardening steels include 410 and 420 grades.
3.2. Stainless Steel Grades
Looking at the family of stainless steels only tells you one part of the properties they possess. To truly understand and differentiate one type of stainless steel from another, you will have to look at the stainless steel grade.
Within each family, there are various stainless steel grades that help to describe specific properties of the alloy, some of them include toughness, magnetism, corrosion resistance and alloy composition.
Older stainless steel grades often feature a three-digit identifier established by the Society of Automotive Engineers (SAE). However, you might also see grades in other formats set by other grading systems; such as the six-character identifier by the American Society for Testing and Materials or identifiers by the International Organisation for Standardisation to name a few.
When you pair a family and grade together, you get a good indication of what to expect from a specific stainless steel alloy.
The two most commonly used stainless steel grades are 316 and 304 stainless steel. The key difference between both grades is the addition of molybdenum, an alloy that drastically enhances the steel’s resistance to corrosion, especially in more saline or chloride-exposed environments.
316 stainless steel contains molybdenum. 304 stainless steel does not.
While 304 stainless steel is an economical and practical choice for more environments, it does not have the chloride resistance of 316 stainless steels. If your facility is frequently exposed to high chloride content, then the slightly higher price point of 316 stainless steel will definitely be worth it.
Here’s a look into both 316 and 304 stainless steels.
3.2.1. 316 Stainless Steel
316 stainless steel falls under the austenitic stainless steel family. It is a chromium-nickel stainless steel that contains between 2% and 3% molybdenum. Its molybdenum content helps to increase corrosion resistance, improve resistance to the breakdown of the chromium oxide layer caused by chloride ions, and increase strength at high temperatures.
The 316-grade stainless steel is especially effective in acidic environments. It can withstand corrosion caused by sulphuric, hydrochloric, acetic, formic and tartaric acids, as well as acid sulfates and alkaline chlorides. This relatively high resistance to chemicals makes them great options for the construction of exhaust manifolds, furnace parts, jet engine parts, pharmaceutical and photography equipment, chemical processing equipment, tanks and evaporators.
Equipment made of 316 stainless steel such as stainless steel shelf racks, work tables, trolleys and more, is ideal for facilities dealing with high amounts of chemical.
The typical chemical composition of 316 stainless steel is as follows:
The typical physical properties of 316 stainless steel are as follows:
3.2.2. 304 Stainless Steel
304 stainless steel is another type of stainless steel that falls under the austenitic family. It is also regarded as the most commonly used austenitic stainless steel.
It contains high nickel content that can sometimes go up to about 35%, high amounts of chromium between 16% and 24%, as well as small amounts of carbon, silicon and manganese. The remainder of the chemical composition is primarily iron.
304 stainless steel can withstand corrosion from most oxidising acids, are easy to sanitise and clean, making them ideal for kitchen and food applications. They are also often used to make equipment such as stainless steel work tables, shelvings and other large storage units.
Although 304 stainless steel is relatively corrosion resistant, it is still susceptible to corrosion from chloride solutions, or from saline environments like the coast. Chloride ions can cause localised corrosion, which can compromise internal structures. Hence, proper maintenance and regular cleaning have to be done to prevent them from sustaining such damages.
The typical chemical composition of 304 stainless steel is as follows:
The typical physical properties of 304 stainless steel are as follows:
CHOOSING A COMMERCIAL STAINLESS STEEL PRODUCT
Stainless steel is a versatile material that was originally used to make cutlery but quickly proved its worth in other industries such as chemical, automobile, and more. Its adaptability was primarily due to its corrosion-resistant properties. However, stainless steels are now being recognized for a variety of other remarkable properties.
4.1. Types of Commercial Steel Products
There are several types of commercial steel products available around the world now due to the development of stainless steel in various grades and families as mentioned above. If you are not sure which product you should be getting for your facility, here are some commercial stainless steel equipment and what they can be used for.
I. Stainless Steel Shelves
Stainless steel shelving racks are often used as storage units in commercial facilities in Singapore. Any industry can make use of stainless steel shelf racks, they are great for storing small to large and bulky items.
Stainless steel shelves will benefit restaurants, medical facilities, cold storage facilities, long term record storage, and retail stores because they are great for efficiently storing items while keeping them visible.
There is also the availability of chrome-plated shelving units you can choose from - chrome plating increases the hardness, durability and corrosion resistance of the stainless steel surface while creating an easy-to-clean shiny and smooth appearance.
II. Perforated Stainless Steel Table
Perforated stainless steel tables are tables that come with holes on the surface, they allow uniformed airflow through the work surface and are ideal for use in cleanrooms.
III. Stainless Steel Work Table
Stainless steel work tables ideal options for use in restaurant preparations, assembly factories and medical offices due to their easy-to-clean surfaces. On top of these businesses, as long as you require a tabletop to work on, a stainless steel work table will be an ideal choice due to its high durability and corrosion resistance.
IV. Stainless Steel Trolley
For any transportation of items, a stainless steel trolley will come in handy no matter which industry you belong to. Use them to facilitate the transfer of food items from cold storage facilities to kitchens or to store and easily move medical supplies and equipment.
V. Stainless Steel Garment Racks
Garment racks allow for convenient storage of lab coats, smocks or garments in medical and/or pharmaceutical facilities. The open wire construction minimises dust buildup and aids air ventilation, which helps to prevent dust and allergens from getting trapped on the surface.
4.2. Things to Note When Choosing A Commercial Stainless Steel Product
When choosing a commercial stainless steel product, consider what you need in your space and what purpose the equipment will serve. Do you need a garment rack to hang up lab coats or a stainless steel work table that can be easily kept clean at all times?
If you need a lot of storage space to store large and bulky items, a good stainless steel shelf rack with solid shelves will be recommended, whereas if you only need to store small and lightweight items, simply opt for a stainless steel shelf rack with