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People often use magnets to verify the authenticity of Stainless Steel. If the SS performs non-magnetic, then 

people think it`s real and good material; Otherwise, it`s fake and unqualified. In fact, this is a one-sided, unrealistic and erroneous method of identification.

There are many types of stainless steel, which can be divided into several types according to the organizational structure at normal temperature:

1. Austenitic type: such as 304, 321, 316, 310, etc.

2. Martensite or Ferrite type: such as 430, 420, 410, etc.

The Austenite type is either non-magnetic or weak magnetic, Martensite or Ferrite type is magnetic.

Commonly, most Stainless Steel used as decorative pipe is 304 in Austenitic type. Generally speaking, it`s non-magnetic or weak magnetic, but during the smelting process, its chemical composition may fluctuate and the processing conditions may be different,which will cause the possibility of magnetic, so we can`t judge the authenticity of SS only by checking it`s magnetic or not.

As we mentioned above, the Austenite is either non-magnetic or weakly magnetic, while the Martensite or Ferrite type is magnetic. But during the actual smelting process, it may happen that small elements of

Martensite or Ferrite exists in the Austerite304 stainless steel. In this way, 304 stainless steel will be with weak magnetic.

In addition, after cold processing, the structure of 304 stainless steel will also be transformed to Martensite, the greater degree of deformation, the more transformation to Martensite. Therefore, the steel will have stronger magnetic .In order to completely eliminate the magnetic properties of 304 steel caused by the above reasons,we can recover the stable Austenite structure by high-temperature solution treatment, thereby eliminating magnetic properties.

One more thing we have to mention, the magnetic properties of 304 stainless steel caused by above reasons are not the same as the magnetic properties of other types of steel such as 430 and carbon steel. That means, the magnetic properties of 304 steel always show weak magnetic .So we can see that if stainless steel is weak magnetic or completely magnetic, it can be judged as SS 304 or 316; if it shows strong magnetic same as carbon steel, then it is not 304 material.