This is why steel is the material of choice for many applications. Medical technology has its own specific requirements when it comes to steel, and the areas of application are diverse:
External equipment - dialysis systems, ventilators, imaging systems, etc.
Implantable medical devices - Orthopaedic, traumatologic and vascular implants
Medical devices - instruments and tools (surgery, orthopaedic and endoscopic accessories, etc.)
Dental products - devices, drills, tools, etc.
Steel solutions for the highest medical requirements
Medical devices are products with a medical purpose that are intended by the manufacturer for use in humans and primarily have a physical effect (e.g. implants, pacemakers, etc.). They are classified and tested according to their risk class (I-III, low to very high).
The Swiss Steel Group manufactures customized products and individual steel solutions for the medical technology and healthcare sectors that are tailored precisely to specific requirements. This steel is characterized by exceptional durability and special properties in terms of wear, strength and flexibility.
State-of-the-art remelting facilities, whether under slag or in a vacuum, produce steels of consistent top quality that meet the highest standards. Using tried and tested processes, the Group guarantees solutions that meet all essential medical quality requirements.
Steels can be exposed to various influences and are used for a wide range of applications. The Swiss Steel Group pays particular attention to the reliability and purity of its steels, which are certified according to ISO and ASTM. With its implantable grades (UGIPURE 4441, UGIPURE 4472, martensitic and austenitic by-products), it has proven itself in the most demanding markets for special properties such as wear resistance, strength or flexibility.
Requirements for all implant materials
1. harmlessness- non-carcinogenic- non-toxic- antigen-free
2. Biological compatibility- No foreign body reaction- Inclusion in the storage metabolism- Biological stability
3. mechanical compatibility- Sufficient mechanical strength- Electrochemical stability (corrosion resistance)- Isoelastic relationship to the bearing fabric
4. functionality- Aesthetically acceptable- cleanability - Radiographic stability
5. handling- Sterilizability- Removability- Machinability
Not all steel is the same
This is because each individual alloy has different mechanical and chemical properties that make it suitable for use in a specific area. This principle applies to medicine in particular.There are two categories of medical steel: materials for instruments and materials for prostheses: Steel for medical devices, also known as surgical steel or simply medical steel, is usually one of the martensitic stainless steels. This steel is often alloyed with chromium and often also contains large amounts of nickel and molybdenum.
The demands on medical steel are high
Hardness: The martensitic transformation of the steel results in a material with excellent hardness and strength. This means that if things get rough during an operation or the doctor hits a bone with his scalpel, his instrument will not break and potentially endanger the patient's life.
Rigidity: Thanks to surgical steel, blades become rigid and their edge remains sharp for a long time. Only in this way is it possible for surgeons to make even longer incisions precisely or to make the smallest incisions, as we know them from minimally invasive operations.
Heat and acid resistance: All instruments are thoroughly cleaned after, before and sometimes even during an operation. This involves not only high heat, but also aggressive substances based on organic acids. Tools made of medical steel, on the other hand, can withstand numerous sterilizations thanks to their heat and acid resistance and work precisely and reliably for a long time.
Corrosion protection: The human body is a real wet biotope, as we consist of up to 80 percent water, and our blood plasma is even 91 percent water. Medical devices are therefore exposed to high levels of moisture during use, not to mention during subsequent cleaning. It is a good thing that stainless steel does not rust.
Scratch-resistant surface: Chrome gives medical instruments a scratch-resistant surface. This is important because even the smallest groove in a tool can become a breeding ground for bacteria, which are quite safe in the material before sterilization.
Hygiene: Speaking of bacteria - they hardly stand a chance on the surface of surgical steel because the alloy has an antibacterial effect.
This means that not just any steel can be used for medical instruments, but only special steels that meet the high requirements of medical technology.
The requirements for implant steel are also high
Stainless steels are also used for many implants and prostheses, but unlike surgical steel, they undergo an austenitic manufacturing process. The materials are freed from numerous metallic impurities and are therefore particularly suitable for their use:
Strength: In this case, strength means the resistance to mechanical stress. A joint replacement must have good strength values, as the new joint is exposed to almost constant movement. Prosthesis steel fulfills this requirement and is therefore particularly durable.
Corrosion protection: Due to the high humidity in the human body, implant steel always has excellent corrosion properties.
Acid resistance: Acids are not only formed during the digestive process. They are also formed as a waste product of cellular energy production and especially during the breakdown of proteins. Although these acids are quickly neutralized by bases, contact with the implant can never be completely ruled out. In modern medicine, implants are coated with a fine layer of anti-inflammatory substances to reduce the body's immune defenses. Acid resistance is and remains a crucial property of implant steel.
Biocompatibility: Biocompatible means that the human body does not fight and reject the foreign material. As prosthesis steel is highly biocompatible, the new body part is not attacked.
Bioadhesion: Bioadhesion means how well the human body can incorporate a prosthesis into natural tissue. Stainless steels have lower adhesion properties and must therefore often be fixed with cement. However, there are also more modern titanium-based materials that have such high bioadhesion that they can be fully incorporated into the natural bone structure after a short time and without any cement.
Implant steels are just as special steels as surgical steels. They require their special properties in order to be suitable for use in the human body.
A historical example at the end
As is well known, Götz von Berlichingen wore a metal prosthetic arm - a true masterpiece of medieval blacksmithing. The "Iron Fist" was equipped with adjustable fingers that returned to their original position at the touch of a button. This iron prosthesis can still be admired today in the Jagsthausen Museum.
A lot of time has passed since then. Prostheses are no longer made of iron, but of modern high-performance materials. Nowadays, thankfully, doctors are able to replace entire joints and bones with implants. Surgery is no longer performed with a rusty saw and a good swig of brandy, but with the help of precision instruments that can work with nanometer accuracy.
Of course, these advances are not only thanks to medicine, but also to metallurgy. Numerous procedures and treatment techniques were only made possible by a material with which the Swiss Steel Group is particularly well versed: steel.