How is surgical stainless steel different from ordinary stainless steel?
I knew keeping my old metallurgy textbook would come in handy. To begin with, there is no such this as “ordinary stainless steel”. There are some 200 alloys on the market that are classified as stainless steels (SS), although there are, perhaps, only 15 or 20 in common use. A stainless steel is a high-alloy steel with a minimum Chromium content of 10.5%. Surgical-grade SS products have to meet certain criteria. They need to be very resistant to corrosion, in particular to those chemicals found within the human body. They cannot be toxic or provoke a reaction from the immune system. As with any material intended for manufacture, SS alloys go through a selection process to match the material properties to the specific application. For example, surgical SS parts do not need to be welded, so a designer could ignore alloys designed for this process. They are usually not machined, so a free-machining SS may not be required. A designer would want to select a high-strength alloy, with low brit
