Properties of Surgical Stainless Steel

Stainless steel is the common name for various types of metal alloys consisting of at least 10.5 percent chromium and 50 percent iron, according to the American Iron and Steel Institute. Surgical stainless steel is a type of steel known as austenitic steel. Surgical stainless steel, also often referred to as implant grade stainless steel, differs from other types of stainless steel in that it typically contains approximately 18 percent chromium and 8 percent nickel and is not hardened by heat.

Nonporous

• Like other forms of steel, surgical stainless steel is nonporous. While steel isn't truly stainless, as the name implies, its nonporous quality makes it highly stain-resistant, since surface substances can be easily wiped away. This quality is particularly important for surgical applications because dirt, grime and microbes can't penetrate the metal's surface, so it is highly hygienic and easily sterilized.

Corrosion Resistant

• Generally, the higher the chromium content, the more resistant to corrosion stainless steel is. This is why surgical stainless steel is particularly resistant to corrosion. Pure iron rusts easily. However, the chromium in surgical stainless steel reacts with the oxygen in the air to create an invisible barrier, preventing the iron and oxygen from combining to form rust. This is important for steel used for piercing and implantation because bodily fluids are highly caustic, notes Cheyenne Morrison, the proprietor of the Piercing Temple in Cairns Australia, in an article published by BMEzine, titled "Surgical Stainless Steel: The Definitive Standards, Specifications, and Tests."

Hypoallergenic

• Surgical stainless steel is very hypoallergenic material, which means that very rarely do people experience allergic reactions to this material, according to Morrison. While many implant devices are made of more inert materials like titanium and titanium stainless steel, many others, such as bone screws and pins, continue to be made of surgical stainless steel, since allergies are so rare, Morrison notes.

Smooth Finish

• Surgical stainless steel typically has a smoother surface finish than other types of stainless steel. This is important when using this metal for surgical purposes because any surface imperfection, however minute, can impair the process of scar formation and healing, notes Sean Christian of Anatometal Inc. Body Jewelry in Santa Cruz, California, in report presented at the 1998 Association of Professional Piercers Open Meeting. This high polish is achieved through a three-step process that includes tumbling, buffing and cleaning with a soft flannel buffing pad or powdered chalk. Having a surface that is completely free of nicks and scratches prevents bacterial colonization, Christian added.