Surgical stainless steel is a grade of

stainless steel Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's corros ...

used in biomedical applications. The most common "surgical steels" are

austenitic Austenite, also known as gamma-phase iron (γ-Fe), is a metallic, non-magnetic allotrope of iron or a solid solution of iron with an alloying element. In plain-carbon steel, austenite exists above the critical eutectoid temperature of 1000 ...

SAE 316 stainless and

martensitic Martensite is a very hard form of steel crystalline structure. It is named after German metallurgist Adolf Martens. By analogy the term can also refer to any crystal structure that is formed by diffusionless transformation. Properties Mart ...

SAE 440, SAE 420, and 17-4 stainless steels. There is no formal definition on what constitutes a "surgical stainless steel", so product manufacturers and distributors often apply the term to refer to any grade of corrosion resistant steel.

Medical grade stainless

SAE 316 and

SAE 316L stainless steel SAE 316L grade stainless steel, sometimes referred to as A4 stainless steel or marine grade stainless steel, is the second most common austenitic stainless steel after 304/A2 stainless steel. Its primary alloying constituents after iron, are c ...

, also referred to as ''

marine grade stainless Marine grade stainless alloys typically contain molybdenum to resist the corrosive effects of NaCl or salt in seawater. Concentrations of salt in seawater can vary, and splash zones can cause concentrations to increase dramatically from the spray ...

'', is a

chromium Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hardne ...

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...

molybdenum Molybdenum is a chemical element with the symbol Mo and atomic number 42 which is located in period 5 and group 6. The name is from Neo-Latin ''molybdaenum'', which is based on Ancient Greek ', meaning lead, since its ores were confused with lea ...

alloy An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, ...

of steel that exhibits relatively good strength and corrosion resistance. 316L is the low carbon version of 316 stainless steel. 316L in particular is biocompatible when produced to ASTM F138 / F139. It is a common choice for biomedical implants, as well as

body piercings Body piercing, which is a form of body modification, is the practice of puncturing or cutting a part of the human body, creating an opening in which jewelry may be worn, or where an Implant (medicine), implant could be inserted. The word ''pier ...

and

body modification Body modification (or body alteration) is the deliberate altering of the human anatomy or human physical appearance. In its broadest definition it includes skin tattooing, socially acceptable decoration (''e.g.'', common ear piercing in many s ...

implants. Immune system reaction to nickel is a potential complication of stainless steel usage within the human body. There are nickel-free

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

-strengthened

stainless steel alloys available which address this concern. 316 surgical steel is also used in the manufacture and handling of food and pharmaceutical products where it is often required in order to minimize metallic contamination. The corrosion resistance properties of all stainless steels is greatly enhanced by the passivation process. ASTM A967 details this process.

Cutlery grade stainless

SAE 440 and SAE 420 stainless steels, known also by the name "Cutlery Stainless Steel", are high carbon steels alloyed with chromium. They have very good corrosion resistance compared to other cutlery steels, but their corrosion resistance is inferior to 316 stainless. Surgical cutting instruments are often made from 440 or 420 stainless due to its high hardness coupled with acceptable corrosion resistance. This type of stainless steel may be slightly magnetic. General surgical tools are made from other chromium-bearing stainless steels, such as 17-4. ASTM F899 contains a list of commonly used metals for

surgical instruments A surgical instrument is a tool or device for performing specific actions or carrying out desired effects during a surgery or operation, such as modifying biological tissue, or to provide access for viewing it. Over time, many different kinds of ...

References

{{Authority control Biomaterials Stainless steel Surgical instruments

Medical grade stainless

Cutlery grade stainless

See also

References