|MadSci Network: Physics|
According to Encyclopedia Britannica Online, there are three types of stainless steels, austenitic, ferritic and martensitic. The austenitic steels are nonmagnetic, but the other two types are magnetic. All steels are metallic alloys. Any metal will block electromagnetic radiation at frequencies below its plasma frequency, which is typically in the near ultraviolet part of the EM spectrum.
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