There are many alloys which make up the stainless steel family but the standard (18:8) stainless steel has the following typical composition
Carbon.................. 0.08% max
Silicon .................. 1. 00% max
Manganese.................. 2.00% max
Chromium.................. 18.00/20.00%
Phosphorus.................. 0.045% max
Nickel.................. 8.00-10.5%
Sulfur.................. 0.030% max
The remainder being Iron