Alloy  Finish    Stained    %Rusted   Pit Density
                % of Area   26 years   ASTM B-537
               |          |          |           |
201      CR    |    15    |    1     |     7     |
301      CR    |    20    |    3     |     8     |
302      CR    |     5    |    3     |     8     |
304      CR    |     3    |    0     |     8     |
304L     2B    |    15    |    3     |     9     |
316      CR    |     2    |    0     |     9     |
316L     2B    |     1    |    0     |    10     |
321      2B    |    10    |    5     |     8     |
347      2B    |    15    |    5     |     8     |
410      No 2  |   100    |   80     |     1     |
430      CR    |   100    |   20     |     8     |

Reference: Baker, E.A. and Lee, T.S. "Long Term Atmospheric Corrosion
       Behaviour of Various Grades of Stainless Steels".  ASTM Symposium
       on Degradation of materials in the Atmosphere.  Philadelphia, PA.
       May 12-13, 1986