Some examples for allowable stress values "S" of typical carbon steels according to Section II, Part D, Table 1A, metric.

NB: Please use Section II Part D for all permitted ASME materials.

for interpolation consider General Notes (b):
The stress values in this Table may be interpolated to determine values for intermediate temperatures. The values at intermediate temperatures shall be rounded to the same number of decimal places as the value at the higher temperatur between which values are being interpolated.The rounding rule is:
when the next digit beyond the last place to be retained is less than 5, retain unchanged the digit in the last place retained; when the digit next beyond the last place to be retained is 5 or greater, increase by 1 the digit in the last place retained.

Due to the relatively low yield strength of these materials, these higher stress values were established at temperatures where the short - time tensile properties govern to permit the use of these alloys where slightly greater deformation is acceptable. The stress values in this range exceed 66 2/3 % but do not exceed 90% of the yield strength at temperature. Use of these stresses may result in dimensional changes due to permanent strain. These stress values are not recommended for the flanges of gasketed joints or other applications where slight amounts of distortion can cause leakage or malfunction. For Section III applications, Table Y - 2 lists multiplying factors that, when applied to the yield strength values shown in Table Y - 1, will give allowable stress values that will result in lower levels of permanent strain.

Upon prolonged exposure to temperatures above 425°C, the carbide phase of carbon steel may be converted to graphite. See Nonmandatory Appendix A, A - 201 and A - 202.

At temperatures above 550°C, these stress values apply only when the carbon is 0.04% or higher on heat analysis.

For Section I, use is limited to PEB - 5.3. See PG - 5.5 for cautionary note.

A factor of 0.85 has been applied in arriving at the maximum allowable stress values in tension for this material. Divide tabulated values by 0.85 for maximum allowable longitudinal tensile stress.

For temperatures above 550°C, these stress values may be used only if the material is heat treated by heating to the minimum temperature specified in the material specification, but not lower than 1040°C, and quenching in water or rapidly cooling by other means.

For Section I applications, stress values at temperatures of 450°C and above are permissible but, except for tubular products 75 mm O.D. or less enclosed within the boiler setting, use of these materials at these temperatures is not current practice.

Allowable stresses for temperatures of 370°C and above are values obtained from time - dependent properties.

Allowable stresses for temperatures of 400°C and above are values obtained from time - dependent properties.

Allowable stresses for temperatures of 565°C and above are values obtained from time - dependent properties.

Allowable stresses for temperatures of 595°C and above are values obtained from time - dependent properties.

Allowable stresses for temperatures of 620°C and above are values obtained from time - dependent properties.

These S values do not include a longitudinal weld efficiency factor. For Section III applications, for materials welded without filler metal, ultrasonic examination, radiographic examination, or eddy current examination, in accordance with NC - 2550, shall provide a longitudinal weld efficiency factor of 1.00. Materials welded with filler metal meeting the requirements of NC - 2560 shall receive a longitudinal weld efficiency factor of 1.00. Other longitudinal weld efficiency factors shall be in accordance with the following:
(a) for single butt weld, with filler metal, 0.80
(b) for single or double butt weld, without filler metal, 0.85
(c) for double butt weld, with filler metal, 0.90
(d) for single or double butt weld, with radiography, 1.00

These S values do not include a weld factor. For Section VIII, Division 1, and Section XII applications using welds made without filler metal, the tabulated tensile stress values shall be multiplied by 0.85. For welds made with filler metal, consult UW - 12 for Section VIII, Division 1, or TW - 130.4 for Section XII, as applicable.