Steel is the most common material used in metal furniture, but which steels can be used to produce furniture, what are their differences, and which is better? Keep reading, and you will get all the answers.
What kind of steel is used in the furniture?
Steels for making furniture are mainly carbon steel and stainless steel.
Carbon steel can divides into three categories according to carbon content:
- Low-carbon steel (less than 0.25% carbon content)
- Medium-carbon steel (about 0.25~0.6% carbon content) carbon content
- High-carbon steel (more than 0.6% carbon)
Generally speaking, the carbon steel used for furniture production is low-carbon steel. Although High-carbon steel has high hardness and strength, but it is brittle and easy to break. While low-carbon steel has good flexibility to machine easily and deforms under stress without breaking, its good weldability is conducive to furniture styling.
Like carbon steel, the basic composition of stainless steel is carbon and steel; but stainless steel contains more than 10.5% chromium for higher corrosion resistance.
And stainless steel has different grades and categories. It can add other metal elements such as cobalt, nickel, tungsten, titanium molybdenum, manganese, and silicon to improve corrosion resistance, strength, toughness, hardness, etc.
Stainless steel is ductile, weldable, and widely used in furniture production. According to furniture design, it can be cut, welded, polished, etched, or hammered with different finishes and colors.
What is the difference between carbon steel and stainless steel?
Stainless steel and carbon steel have the same basic composition, and both come in different types and grades(hard and soft, strong and weak, flexible and rigid) for different functionalities and uses. They are similar, and yet they are different.
The most significant difference between stainless steel and carbon steel is their ability to corrosion resistance.
Low-carbon steel has low chromium content and is easy to rust, which is also the fatal disadvantage of its use for furniture. When carbon steel is used in humid environments, the iron in carbon steel will react with moisture and oxygen to form iron oxide, which comes to rust.
Stainless steel contains more than 10.5% chromium, which reacts with oxygen to form a passivation layer on the surface of stainless steel – chromium oxide. It barries the iron reacts with oxygen, protecting internal steel from oxidation. Chromium oxide has self-healing properties to repair even if damaged, providing continuous protection. The higher the chromium, the stronger the corrosion protection.
Besides chromium, high-grade stainless steel added more metal elements to improve its corrosion resistance. For example, stainless steel 304 adds 8% nickel (316 adds 10%), higher oxidation resistance, and a wider range of the passivation layer.
To adapt to more extreme environments, stainless steel 316 adds 2%-3% molybdenum to expand the passivation range further and improve corrosion resistance. Therefore it can adapt to high salt, high temperature, high humidity, and chloride environment.
Risk of sensitization
Welding is a necessary process in furniture production. While welding, the temperature is very high, and steel might be sensitization: the carbon in the steel interacts with the chromium and forms chromium carbide, resulting in a lack of surrounding chromium, reducing corrosion resistance, and leading to rust.
The higher the carbon content, the more chromium needs to be consumed and the higher risk of corrosion occurs. Compared to stainless steel, carbon steel has more carbon and is easier to sensitization and corrosion.
Another significant difference between carbon steel and stainless steel is their cost, even though the prices of materials are always changing. But generally speaking, low-carbon steel has a huge advantage over stainless steel.
According to data on Alibaba, the raw material price of low-carbon steel is $600.00-$669.00. / ton, while stainless steel 304 is $1,550.00-$1,730.00. The material cost of stainless steel is three to four times that of carbon steel. (Note: prices vary depending on the grade of material)
Stainless steel and carbon steel are different in appearance, which can be seen in the eyes.
Stainless steel does not need a coating and comes with a glossy metallic surface and smooth touch. Its protective layer- chromium oxide, protects it from corrosion and remains shiny. With correct maintenance, stainless steel can keep this beautiful appearance long.
On the other hand, most carbon steel has a matte finish and is dull in color. It needs to be sanded and polished to get a smooth finish. But its surface is easy to get pollution and corrosion, and if the polished carbon steel is not coated with varnish or paint as soon as possible, it will easily discolor stain and rust.
corrosion Resistance: Stainless steel ＞Carbon steel
Risk of sensitization: Stainless steel ＜Carbon steel
Cost: Stainless steel ＞Carbon steel
Appearance: Stainless steel is shiny and bright color; Carbon steel is a matt and dark color
Carbon steel VS Stainless steel, Which is better for furniture?
Per physical performance, it’s hard to tell who’s better or worse because they both meet the furniture demands. Here are some reference data for their use as furniture material:
|Furniture use||Carbon Steel||Stainless steel|
|Uses||Indoor furniture||Indoor & Outdoor Furniture|
|Service life||Long-time life (with anti-rust treatment)||A longer time than carbon steel|
|Cost||Low||Higher than mild steel|
Put the price aside, compared with carbon steel, stainless steel is better for furniture. Because the furniture is not required to be frequently replaced, while stainless steel has a longer life due to its corrosion resistance.
Even after anti-rust treatment, carbon steel still can’t compare with stainless steel at Corrosion Resistance.
Especially if you live near the sea or use it as outdoor furniture, there is no doubt to choose stainless steel for furniture.