A diagram proposed by A. E. Schaeffler in 1956 to predict the ferrite number (FN)of a stainless steel weld deposit. The user calculated the chromium and nickel equivalents of the deposit, based on weld chemistry, and was able to plot the ferrite number. The Schaeffler Diagram was followed by the DeLong diagram (proposed by W. T. DeLong in 1974), the Espy Diagram (proposed by R. H. Espey in 1982), and the WRC-1992 Diagram (developed by a Welding Research Council Sub-committee in 1992 and described in WRC Bulletin 342. See DELONG DIAGRAM, WRC-1988 DIAGRAM, and ANSI/AWS A5.4, Specification for Stainless Steel Electrodes for Shielded Metal Arc Welding.