ASTM A403 Standard Specification for Austenitic Stainless Steel Piping Fittings

Material are available in ASTM A403 WP304/304L,WP316/316L,WP317/317L, ASTM A403 WP310S,ASTM A403 WP321,ASTM A403 WP321H, ASTM A403 WP347, WP347H

ASTM A403 Manufacture

1 Forming—Forging or shaping operations may be performed by hammering, pressing, piercing, extruding, upsetting, rolling,
bending, fusion welding, machining, or by a combination of two or more of these operations. The forming procedure shall be so
applied that it will not produce injurious defects in the fittings.
2 All fittings shall be heat treated in accordance with Section 6.
3 Grade WP fittings ordered as Class S shall be of seamless construction and shall meet all requirements of ASME B16.9,
ASME B16.11, MSS SP-79, MSS SP-83, MSS SP-95, or MSS SP-97

ASTM A403 Heat Treatment

6.1 All fittings shall be furnished in the heat-treated condition. For H grades, separate solution heat treatments are required for
solution annealing; in-process heat treatments are not permitted as a substitute for the separate solution annealing treatments. The
heat-treat procedure, except for those grades listed in 6.2, shall consist of solution annealing the fittings at the temperatures listed
for each grade in Table 4 until the chromium carbides go into solution, and then cooling at a sufficient rate to prevent
reprecipitation.
6.2 A solution annealing temperature above 1950 °F [1065 °C] may impair the resistance to intergranular corrosion after
subsequent exposure to sensitizing conditions in 321, 321H, 347, and 347H. When specified by the purchaser a lower temperature
stabilizing treatment or a second solution anneal shall be used subsequent to the initial high-temperature solution anneal (see
Supplementary Requirement S2).
6.3 All welding shall be done prior to heat treatment.

ASTM A403 Chemical Composition

The chemical composition of each cast or heat used shall be determined and shall conform to the requirements of the chemical composition for the respective grades of materials listed in Table 2. The ranges as shown have been expanded to include variations of the chemical analysis requirements that are listed in the various specifications for starting materials (pipe, tube, plate, bar, and forgings) normally used in the manufacturing of fittings to this specification. Methods and practices relating to chemical analyses required by this speci-fication shall be in accordance with Test Methods, Practices, and Terminology A 751. Product analysis tolerances in accor-dance with Specification A 480/A 480M are applicable.

ASTM A403 Tensile Properties

The tensile properties of the Testing material shall con-form to the requirements of Table 4. The testing and reporting shall be performed in accordance with Test Methods and Definitions A 370.

ASTM A403 Dimensions

1 For fittings covered by ASME B16.9, ASME B16.11, MSS SP-43, or MSS SP-79, the sizes, shapes, and dimensions of the fittings shall be as specified in those standards.

• Dimensional Standards: ASME B16.9, ASME B16.28, MSS-SP-43

• End Type: Beveled ends (for butt weld), as per ASME B16.25

• Sizes: ½” to 48″ (DN15 to DN1200)

1.1 Fittings of size or shape differing from these stan-dards, but meeting all other requirements of this specifiation, may be furnished in accordance with Supplementary Require-ment S58 Specification A 960.

ASTM A403 Product Marking

All fittings shall have the prescribed information stamped or otherwise suitably marked on each fitting inaccordance with the latest edition of MSS SP-25. See Table 5 for marking examples of grades and classes.