Both the material properties and their structure make it magnetic. Here is a breakdown of their structure: https://www.accu.co.uk/en/p/112-difference-between-ferritic-austenitic-and-martensitic-stainless-steels
Arkie, I've recently discovered that cold working Austentic steel (even just bending it) changes the structure of the iron atoms, which turns some of it into Martensitic. So I wonder if perhaps your medical forceps were stainless steel grade 304? Does anyone know if there is a better method of testing stainless steel to see what type it is?