Pitting Resistance Equivalent Number (PREN)

Written by Jerry Ratzlaff on . Posted in Metal

PERN is a way to measure the pitting corrosion resistance of various types of stainless steel in a chlorine based environment.  The composition of the stainless steel will affect the corrosion resistance.

Pitting Resistance Equivalent Number (PREN) Formula

\(\large{ PERN  =  C \;+\; \left( 3.3 * M  \right)  \;+\;   \left( 16 * N  \right)  }\)         


\(\large{ PERN }\)   (Greek symbol alpha) = pitting resistance equivalent number

\(\large{ C }\) = chromium in percentage

\(\large{ M }\) = moybdenum in percentage

\(\large{ N }\) = nitrogen in percentage


Tags: Equations for Corrosion