JULY JLC 1998 Galvanized Hardware To the Editor: The item on galvanized fasteners (On the House, 2/98) was informative to a point. After comparing three galvanizing processes with zinc coatings ranging from 0.14 mils to 6.0 mils thick, with two of the three processes producing coatings less than 0.3 mils thick, the graph shows service life expectancy starting at 0.4 mils. Since some common fasteners (electroplated and mechanically galvanized) have less than a 0.4-mil coating, should we expect those fasteners to have no service life? And why would a suburban exposure be more severe than a tropical marine exposure? I'd have thought the tropical marine area to be one of the worst. John P. Callen, P.E. Hilo, Hawaii Suk Lee, of the