This Surface Preparation Commentary (SP COM) is intended to be an aid in selecting the proper surface preparation method@ materials@ and specification for steel@ concrete@ and other metallic substrates. A compilation of standards@ guides@ and specifications related to the surface preparation and coating of concrete is available as a separate publication from SSPC. The SP COM is not part of the actual specification@ but is included to provide a better understanding of the SSPC surface preparation specifications. In addition@ surface preparation specifications other than those published by SSPC are referenced. The SSPC specifications@ summarized in Table 1@ represent a broad consensus of users@ suppliers@ and public interest groups. Details of the methods used to measure many of the properties in this SP COM are described in SSPC publication 97-07@ The Inspection of Coatings and Linings@ A Handbook of Basic Practice for Inspectors@ Owners@ and Specifiers.