A common class of instruments that use stainless steel are surgical instruments. These are the cutting, probing and clamping tools that doctors use during surgery, where hygiene is very important. You need tools that can be thoroughly sterilized and will not corrode despite exposure to potentially corrosive liquids.
Another device that may be made of stainless steel is an implantable device that is temporarily or permanently inserted into the body. From pins or screws used to fix broken bones to artificial heart valves. In either case, the device must be durable, even in a human environment.
In addition to what has already been mentioned, the list of medical devices that rely on stainless steel includes precision tubes, mandrels, chemical and hazardous waste containers, needles, catheters, prosthetics, curettes, cutting tools and sheet metal, among others. In addition, auxiliary items that must also be sterilized will also be made of stainless steel, such as trays, countertops, bowls, sinks, etc.