Which one of the following metal is NOT an essential component in stainless steel?

The correct answer is Tin.

Key Points

• Although tin is used in various alloys and has its own unique characteristics, it is not a common component of stainless steel.
  • Adding tin to stainless steel is not common and is not considered a standard ingredient in stainless steel production.
• Stainless steel is primarily composed of iron, along with chromium, nickel, and other elements. 
  • Chromium provides corrosion resistance to steel.
  • It exhibits exceptional corrosion resistance due to the formation of a very thin layer of Cr₂O₃ on the surface.
  • Nickel is usually added to stainless steel to increase its strength and hardness. It also improves corrosion resistance, especially in acidic environments.
  • An important type of stainless steel is often described as 18/8 steel where the chromium and nickel percentages are 18 and 8 respectively.