Determining whether Galvanized or Stainless Steel 2

[KdKato]

Are there any tests that can be performed to determine if our conduit connections are galvanized or stainless steel?

If so how do I go about testing the material.

Thanks

 

[metengr]

I would start with the basic test, one of the fundamental sorting tools, a magnet. If the connections are slightly magnetic or nonmagnetic, they would be an austenitic stainless steel (3xx). However, there are grades of stainless which are magnetic, see below.

If the connections are magnetic, they could be a ferritic stainless steel or galvanized. In this case, remove one and visually look to see if it has a grayish colored surface coating, if so it would be galvanized. If it is polished, it could be a ferritic stainless steel.

 

[CoryPad]

A drop of hydrochloric acid will differentiate the two. Galvanized will bubble while stainless will be relatively unaffected.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[limey1]

Do you have a portable PMI or spark tester?.

 

[strider6]

i'll try the magnet. I think that it will be very unusual a martensitic or ferritic SS.

S.

Corrosion Protection & Corrosion Control