304 stainless steel contains chromium (min. 18%), and nickel (min. 8%). It is an austenite steel and is only slightly responsive to magnetic fields. It also contains 18 – 20% chromium and 8-10.50% nickel, and lesser quantities of some other elements.
 
316 stainless steel is a molybdenum-alloyed steel. The fact that it is also negligibly responsive to magnetic fields means that it can be used in applications where a non-magnetic metal is required. It also contains a number of other elements in varying concentrations.
 
However, this does not mean that you should expect to measure such a low susceptibility on any item of 304 or 316 stainless steel wire mesh / basket cable trays that you encounter. Any process which can change the crystal structure of stainless steel can cause austenite to be converted to the ferromagnetic martensite or ferrite forms of iron. These processes include cold working and welding, which are involved during wire mesh / basket cable tray manufacture.
 
The material we purchased to manufacture basket cable trays is drawn down from 8mm rod to target wire gauge. This mechanical process will make the SS304 and SS316 wires attract magnet. It’s important to understand when selecting a grade of stainless steel (SS) for basket cable tray if the application needs to avoid magnetic properties or not.