ASTM A403/A403M − 2022 is a standard specification for the manufacturing and acceptance of stainless steel and alloy steel pipe fittings. Specifically, it provides the requirements for materials, design, manufacturing, testing, and acceptance of welded pipe fittings, such as elbows, tees, reducers, flanges, and more.
Standard Specification for Wrought Austenitic Stainless Steel Piping Fittings
This specification covers wrought stainless steel fittings for pressure piping applications.
Several grades of austenitic stainless steel alloys are included in this specification. Grades are designated with a prefix, WP or CR, based on the applicable ASME or MSS dimensional and rating standards, respectively.
For each of the WP stainless grades, several classes of fittings are covered to indicate whether seamless or welded construction was utilized. Class designations are also used to indicate the nondestructive test method and extent of nondestructive examination (NDE). Table 1 provides a general summary of the fitting classes applicable to all WP grades of stainless steel covered by this specification. There are no classes for the CR grades. Specific requirements are detailed elsewhere.
A403/A403M -22 Chemical Requirement
- NOTE 1—Where an ellipsis (…) appears in this table, there is no requirement and the element need neither be analyzed for or reported.
| GradeA | Composition,% | ||||||||||||
| Grade WP | Grade CR | UNS Designation | Carbon【B】 | Manganese【B】 | Phoshorous【B】 | Sulphur【B】 | Silicon【B】 | Nickel | Chromium | Molybdenum | Titanium | Nitrogen【C】 | Others |
| WPXM-19 | CRXM-19 | S20910 | 0.06 | 4.0-60 | 0.045 | 0.030 | 1.00 | 11.5-13.5 | 20.5-23.5 | 1.50-3.00 | … | 0.20-0.40 | 【E】 |
| WP20CB | CR20CB | N08020 | 0.07 | 2.00 | 0.045 | 0.035 | 1.00 | 32.0-38.0 | 19.0-21.0 | 2.00-3.00 | … | … | Cu 3.0-4.0 Nb【D】8XC min, 1.00 max |
| WP6XN | CR6XN | N08367 | 0.03 | 2.00 | 0.040 | 0.030 | 1.00 | 23.5-25.5 | 20.0-22.0 | 6.0-7.0 | … | 0.18-0.25 | Cu 0.75 |
| WP700 | CR700 | N08700 | 0.04 | 2.00 | 0.040 | 0.030 | 1.00 | 24.0-26.0 | 19.0-23.0 | 4.3-50 | … | … | Cu 0.50 Nb【D】8XC min |
| WPNIC | CRNIC | N08800 | 0.10 | 1.50 | 0.045 | 0.015 | 1.00 | 30.0-35.0 | 19.0-23.0 | … | 0.15-0.60 | … | Al 0.15-0.60 Cu 0.75 Fe 39.5 min |
| WPNIC10 | CRNIC10 | N08810 | 0.05-0.10 | 1.50 | 0.045 | 0.015 | 1.00 | 30.0-35.0 | 19.0-23.0 | … | 0.15-0.60 | … | Al 0.15-0.60 Cu 0.75 Fe 39.5 min |
| WPNIC11 | CRNIC11 | N08811 | 0.06-0.10 | 1.50 | 0.040 | 0.015 | 1.00 | 30.0-35.0 | 19.0-23.0 | … | 0.25-0.60【M】 | … | AI 0.25-0.60【M】 Cu 0.75 Fe 39.5 min |
| WP904L | CR904L | N08904 | 0.02 | 2.00 | 0.045 | 0.035 | 1.00 | 23.0-28.0 | 190-23.0 | 4.0-5.0 | … | 0.1 | Cu 1.0-20 |
| WP1925 | CR1925 | N08925 | 0.02 | 1.00 | 0.045 | 0.030 | 0.50 | 24.0-26.0 | 19.0-21.0 | 6.0-7.0 | … | 0.10-0.20 | Cu 0.8-1.5 |
| WP1925N | CR1925N | N08926 | 0.02 | 2.00 | 0.030 | 0.010 | 0.50 | 24.0-26.0 | 19.0-21.0 | 6.0-7.0 | … | 0.15-0.25 | Cu 0.5-1.5 |
| WP304 | CR304 | S30400 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 8.0-11.0 | 18.0-20.0 | … | … | … | … |
| WP304L | CR304L | S30403 | 0.030F | 2.00 | 0.045 | 0.030 | 1.00 | 8.0-12.0 | 18.0-20.0 | … | … | … | … |
| WP304H | CR304H | S30409 | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 8.0-11.0 | 18.0-20.0 | … | … | … | … |
| WP304N | CR304N | S30451 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 8.0-11.0 | 18.0-20.0 | … | … | 0.10-0.16 | … |
| WP304LN | CR304LN | S30453 | 0.03 | 2.00 | 0.045 | 0.030 | 1.00 | 8.0-11.0 | 18.0-20.0 | … | … | 0.10-0.16 | … |
| WP309 | CR309 | S30900 | 0.20 | 2.00 | 0.045 | 0.030 | 1.00 | 12.0-15.0 | 22.0-24.0 | … | … | … | … |
| WP310S | CR310S | S31008 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 19.0-220 | 24.0-26.0 | … | … | … | … |
| WP310H | CR310H | S31009 | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 19.00-22.0 | 24.0-26.0 | … | … | … | … |
| WPS31254 | CRS31254 | S31254 | 0.02 | 1.00 | 0.030 | 0.010 | 0.80 | 17.5-18.5 | 19.5-20.5 | 6.0-6.5 | … | 0.18-0.25 | Cu 0.50-1.00 |
| WPS31266 | CRS31266 | S31266 | 0.03 | 2.00-4.00 | 0.035 | 0.020 | 1.00 | 21.00-24.00 | 23.00-25.00 | 5.2-6.2 | … | 0.35-0.60 | Cu 1.00-2.50 W 1.50-2.50 |
| WP316 | CR316 | S31600 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 10.0-14.0 | 16.0-18.0 | 2.00-3.00 | … | … | … |
| WP316L | CR316L | S31603 | 0.030【F】 | 2.00 | 0.045 | 0.030 | 1.00 | 10.0-14.0【G】 | 16.0-18.0 | 2.00-3.00 | … | … | … |
| WP316H | CR316H | S31609 | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 10.0-14.0 | 16.0-18.0 | 2.00-3.00 | … | … | … |
| WP316N | CR316N | S31651 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 10.0-13.0 | 16.0-18.0 | 2.00-3.00 | … | 0.10-0.16 | … |
| WP316LN | CR316LN | S31653 | 0.03 | 2.00 | 0.045 | 0.030 | 1.00 | 10.0-13.0 | 16.0-18.0 | 2.00-3.00 | … | 0.10-0.16 | … |
| WP317 | CR317 | S31700 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 11.0-15.0 | 18.0-20.0 | 3.0-4.0 | … | … | … |
| WP317L | CR317L | S31703 | 0.03 | 2.00 | 0.045 | 0.030 | 1.00 | 11.0-15.0 | 18.0-20.0 | 3.0-4.0 | … | … | … |
| WPS31725 | CRS31725 | S31725 | 0.03 | 2.00 | 0.045 | 0.030 | 1.00 | 13.5-17.5 | 18.0-20.0 | 4.0-5.0 | … | 0.2 | … |
| WPS31726 | CRS31726 | S31726 | 0.03 | 2.00 | 0.045 | 0.030 | 1.00 | 13.5-17.5 | 17.0-20.0 | 4.0-50 | … | 0.10-0.20 | … |
| WPS31727 | CRS31727 | S31727 | 0.03 | 1.00 | 0.030 | 0.030 | 1.00 | 14.5-16.5 | 17.5-19.0 | 3.8-4.5 | … | 0.15-0.21 | Cu 2.8-4.0 |
| WPS31730 | CRS31730 | S31730 | 0.03 | 2.00 | 0.040 | 0.010 | 1.00 | 15.0-16.5 | 17.0-19.0 | 3.0-4.0 | … | 0.045 | Cu 4.0-50 |
| WPS32053 | CRS32053 | S32053 | 0.03 | 1.00 | 0.030 | 0.010 | 1.00 | 24.0-26.0 | 22.0-24.0 | 5.0-6.0 | … | 0.17-0.22 | … |
| WP321 | CR321 | S32100 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 9.0-12.0 | 17.0-19.0 | … | 【H】 | … | … |
| WP321H | CR321H | S32109 | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 9.0-12.0 | 17.0-19.0 | … | 【I】 | … | … |
| WPS33228 | CRS33228 | S33228 | 0.04-0.08 | 1.00 | 0.020 | 0.015 | 0.30 | 31.0-33.0 | 26.0-28.0 | … | … | Ce 0.05-0.10 | |
| WPS34565 | CRS34565 | S34565 | 0.03 | 50-7.0 | 0.03 | 0.01 | 1 | 16.0-18.0 | 23.0-25.0 | 4.0-5.0 | … | 0.40-0.6 | Al 0.025 Nb【D】0.6-1.0 Nb【D】 0.10 |
| WP347 | CR347 | S34700 | 0.08 | 2 | 0.045 | 0.03 | 1 | 9.0-12.0 | 17.0-19.0 | … | … | … | J |
| WP347H | CR347H | S34709 | 0.04-0.10 | 2 | 0.045 | 0.03 | 1 | 9.0-12.0 | 17.0-19.0 | … | … | … | K |
| WP347LN | CR347LN | S34751 | 0.005-0.020 | 2 | 0.045 | 0.03 | 1 | 9.0-13.0 | 17.0-19.0 | … | … | … | Nb【D】0.20-0.50【L】 N 0.06-0.10【C】 |
| WPS34752 | CRS34752 | S34752 | 0.005-0.020 | 200 | 0.035 | 0.01 | 0.6 | 10.0-13.0 | 17.0-19.0 | 0.20-1.20 | … | 0.06-0.12【C】 | Cu 2.50-3.50 Nb【D】0.20-0.50【L】 B 0.001-0.005 |
| WP348 | CR348 | S34800 | 0.08 | 2 | 45 | 0.03 | 1 | 9.0-12.0 | 17.0-19.0 | … | … | … | Nb【D】+Ta=10×【C】-1.10 Ta 0.10 Co 0.20 |
| WP348H | CR348H | S34809 | 0.04-0.10 | 2 | 0.045 | 0.03 | 1 | 9.0-12.0 | 17.0-19.0 | … | … | … | Nb【D】+Ta=8×【C】-1.10 Ta 0.10 |
| WPS38815 | CRS38815 | S38815 | 0.03 | 2 | 0.04 | 0.02 | 5.5-6.5 | 15.0-17.0 | 13.0-15.0 | 0.75-1.50 | … | … | Co 0.20 Cu 0.75-1.50 AI 0.30 |
【A】See Section 15 for marking requirements.
【B】Maximum, unless otherwise indicated.
【C】The method of analysis for nitrogen shallbe a matter of agreement between the purchaser and manufacturer.
【D】Niobium and columbium are interchangeable names for the same element and both names are acceptable for use in A01.22 specifications.
【E】Niobium(columbium)0.10-0.30 %;Vanadium,0.10-0.30%.
【F】For small diameter or thin walls, or both, where many drawing passes are required, a carbonmaximum of0.040 % is necessary in grades TP304L and TP316L. Smalloutside diameter tubes are defined as those less than 0.500 in. [12.7 mm] in outside diameter and light wall tubes as those less than 0.049 in. [1.24 mm] in average wall thickness.
【G】 On pierced tubing, the nickel may be 11.0-16.0%.
【H】5X(C+N) min-0.70 max.
【I】4X(C+N)min-0.70 max.
【J】The niobium (columbium) content shall be not less than ten times the carbon content and not more than 1.10 %.
【K】The niobium (columbium) content shall be not less than eight times the carbon content and not more than 1.10 %.
【L】The niobium (columbium) content shall be not less than 15 times the carbon content.
【M】Al + Ti shall be 0.85 % min: 1.20 % max.
A403/A403M -22 Tensile Requirements
| AlI WP and CR Grades | Yield Strength,min, ksi [MPa] | Tensile Strength, min, ksi [MPa] |
| 304,304LN,304H,309,310S,310H,316,316LN,316H,317,317L,347,347H,347LN,S34752,【B】348,348H,321,321H | 30 [205] | 75[515] |
| Seamless(A312 tubular): | ||
| t≤3/in. | 30 [205] | 75[515] |
| t>3%in. | 25 [170] | 70[485] |
| All other fitting classes: | 30 205] | 75[515] |
| S31266, S31725 | 61 [420] | 109 [750] |
| S31727 | 36 [245] | 80 [550] |
| S31730 | 25[175] | 70[480] |
| S32053 | 43[295] | 93 [640] |
| 304L,316L | 25[170] | 70[485] |
| 304N,316N,S31726 | 35[240] | 80 [550] |
| XM-19 | 55[380] | 100 [690] |
| N08020 | 35[240] | 80 [550] |
| N08367 | 45[310] | 95 [655] |
| N08700 | 35[240] | 80[550] |
| N08800 | 25 [205] | 65[520] |
| N08810 | 25[170] | 65[450] |
| N08811 | 25[170] | 65 [450] |
| N08904 | 31 [220] | 71 [490] |
| N08925 | 43[295] | 87 [600] |
| N08926 | 43[295] | 94 [650] |
| S31254 | 44[300] | 94 [650] to 119 [820] |
| S33228 | 27[185] | 73 [500] |
| S34565 | 60 [415] | 115[795] |
| S38815 | 37 [255] | 78 [540] |
| Elongation Requirements | ||
| Longitudinal | Transverse | |
| Standard round specimen, or small proportional specimen, or strip-type specimen, minimum % in 4 D【A】 | 28 | 20 |
【A】S38815 Elongation in 2 in.-30% min.
【B】S34752 Elongation in 2 in.-35% min.
For more information about ASTM A403, please contact SSM. We provide product and technical service support.
EN 
DE 
RU 
FA 
ID