Mechanical property data for alloys currently produced and used for petroleum refinery heater applications have been gathered and analyzed using systematic computerized statistical data fitting methods. Properties reported for each material are elevated temperature yield and tensile strengths, minimum and average stress-rupture strengths, and stress-rupture exponent at temperature. Whenever possible data gathered were representative of materials produced by modern production methods. The results of the analyses were presented using polynomial equations for stress and temperature dependence of the properties. Stress-rupture test results were used to develop Larson-Miller Parameter relations based on optimized constants for each alloy. Parameter plots for each alloy compare the properties shown in API Std 530 with those obtained from the current analyses. Materials included are: Low and Medium Carbon steels; Carbon-0.5 Mo steel; 1.25 Cr-0.5 Mo steel, 2.25 Cr-1 Mo, 3 Cr-1 Mo steel and 5, 7 and 9 Cr-Mo steels, 9 Cr-1 Mo-V steel and Alloy 115 (10.5Cr-V); Types 304, 304L, 304H, 316, 316L, 316H, 317L, 321, 321H, 347, 347H, 347AP, and Advanced 347AP stainless steels; Alloys 800, 800H and 800HT; and HK-40. In the initial sections of this volume examples are provided demonstrating application of the polynomial equations to common problems such as determining design life at temperature and design allowable stress.