Surgical stainless steel of body piercing jewellery and body modification implants. 440 and 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. Biomedical 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. Surgical stainless steel Surgical stainless steel is a grade of stainless steel used in biomedical applications. The most common "surgical steels" are
SAE 304 stainless steel by SAE International as part of its SAE steel grades. Outside of the US it is commonly known as A2 stainless steel, in accordance with ISO 3506 for fasteners. In the commercial cookware industry it is known as 18/8 stainless steel. In the unified numbering system it is UNS S30400. The Japanese equivalent grade of this material is SUS304.. It is also specified in European norm 1.4301. 304 stainless steel has excellent resistance to a wide range of atmospheric environments and many corrosive media. It is subject to pitting and crevice corrosion in warm chloride environments and to stress corrosion