Different Types of Stainless Steel
There are over 100 alloys of stainless steel, and each is denoted by a unique SAE steel grade number, which may include one or more letters. Stainless steel alloys include steel (iron with carbon), chromium for scratch resistance and corrosion resistance, nickel to reduce brittleness and improve strength at both high and low temperatures, and other trace elements. For stainless steel alloys used in jewelry, these trace elements are approximately 0.75% silicon, 0.045% phosphorous, 0.03% sulfur, 2% manganese, and 0.1% nitrogen.
Out of the many alloys available, 304 Stainless Steel is the most popular grade. It is 18-20% chromium, 8-10.5% nickel, 0.08% carbon, plus iron and the trace elements listed above. It is commonly used in the food industry (sinks, beer/brewing, fruit juice handling, etc). Its corrosion and stain resistance qualities also make it a great product within the jewelry category.