Stainless steel

Stainless steel - it is common to define a group of stainless steels, a little more detail, we can divide them permanently resistant to corrosion and acid resistant steels. Corrosion resistance is achieved by adding to the basic iron alloy suitable additives, usually chromium and nickel.


The most common species of stainless steel are: 18/10 (18% chromium and 10% nickel), 304 - used in the food industry (cutlery, dishes), chemical (installations, pipelines) and medical (tools, implants), and continuously A2 and A4 - which is usually performed fasteners.


"Stainless steel" bolt is made of two types of steel - A2 and A4, wherein it should be noted that:

  • A2 steel - is steel with high corrosion resistance, but not resistant to concentrated acids; In practice, this translates into the fact that the screw is made of this kind of steel exposed to ambient conditions (e.g. rain or moisture) does not cover rust, corrode and can wrap the chemical after acid (e.g. leakage from the battery)
  • A4 steel - is stainless steel, the action of which is based concentrated acids such as sulfuric, phosphoric, acetic, etc. - hence its common use in the chemical industry.