ASTM A403 Stainless Pipe Fitting
Scope of ASTM A403:
- This specification covers wrought stainless steel fittings for pressure piping applications .
- Several grade of austenitic stainless steel alloy are included in this specification grades are designated with a prefix , WP or CR , based on the applicable ASME or MSS dimensional and rating standard, 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 utilized to indicate the non-destructive test method and extent of non-destructive examination (NDE) . Table 1 is a general summary of the fitting classes applicable to all WP grade of stainless steel covered by this specification . There are covered elsewhere.
- This specification is expressed in both inch-pound units and in SI units . However, unless the order specifies the applicable “M” specification designation (SI uints), the material shall be furnished to inch-pound units .
- The values stated in either SI units or inch-pound units are to be regarded separately as standard . Within the text , the SI units are shown in brackets . The values stated in each system may not be exact equivalents ; therefore , each system shall be used independently of the order . Combining values form the two systems may result in non-conformance with the standard .
- This specification does not apply to cast steel fittings . Austenitic stainless steel castings are covered in specifications A351/A351M , A743/A743M , and A744/A744M
Chemical Composition (%) of ASTM A403
| Grade | UNS | C | Mn | P | S | Si | Ni | Cr | Mo |
| 304 | S30400 | 0.008 | 2.00 | 0.045 | 0.030 | 1.00 | 8.0-11.0 | 18.0-20.0 | - |
| 304H | S30409 | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 8.0-11.0 | 18.0-20.0 | - |
| 304L | S30403 | 0.035 | 2.00 | 0.045 | 0.030 | 1.00 | 8.0-13.0 | 18.0-20.0 | - |
| 304LN | S30453 | 0.030 | 2.00 | 0.045 | 0.030 | 0.75 | 8.0-10.5 | 18.0-20.0 | - |
| 304N | S30451 | 0.08 | 2.00 | 0.045 | 0.030 | 0.75 | 8.0-11.0 | 18.0-20.0 | - |
| 309 | S30900 | 0.15 | 2.00 | 0.045 | 0.030 | 1.00 | 12.0-15.0 | 22.0-24.0 | - |
| 310 | S31000 | 0.15 | 2.00 | 0.045 | 0.030 | 1.50 | 19.0-22.0 | 24.0-26.0 | - |
| 316 | S31600 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 10.0-14.0 | 16.0-18.0 | 2.00-3.00 |
| 316H | 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 |
| 316LN | S31653 | 0.030 | 2.00 | 0.045 | 0.030 | 0.75 | 11.0-14.0 | 16.0-18.0 | 2.00-3.00 |
| 316L | S31603 | 0.035 | 2.00 | 0.045 | 0.030 | 1.00 | 10.0-16.0 | 16.0-18.0 | 2.00-3.00 |
| 316N | S31651 | 0.008 | 2.00 | 0.045 | 0.030 | 1.00 | 11.0-14.0 | 16.0-18.0 | 2.00-3.00 |
| 317 | S31700 | 0.008 | 2.00 | 0.045 | 0.030 | 1.00 | 11.0-15.0 | 18.0-20.0 | 3.0-4.0 |
| 317L | S31703 | 0.030 | 2.00 | 0.045 | 0.030 | 1.00 | 1.0011.0-15.0 | 18.0-20.0 | 3.0-4.0 |
| 321 | S32100 | 0.008 | 2.00 | 0.045 | 0.030 | 1.00 | 9.0-13.0 | 17.0-20.0 | - |
| 321H | S32109 | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 9.0-13.0 | 17.0-20.0 | - |
| 347 | S34700 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 9.0-13.0 | 17.0-20.0 | - |
| 347H | S34709 | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 9.0-13.0 | 17.0-20.0 | - |
| 348 | S34800 | 0.008 | 2.00 | 0.045 | 0.030 | 1.00 | 9.0-13.0 | 17.0-20.0 | - |
| 348H | S34809 | 0.04-0.010 | 2.00 | 0.045 | 0.030 | 1.00 | 9.0-13.0 | 17.0-20.0 | - |
| XM-19 | S20910 | 0.060 | 4.0-6.0 | 0.040 | 0.030 | 1.00 | 11.5-13.5 | 20.5-23.5 | 1.5-3.00 |
| S31254 | 0.020 | 1.00 | 0.030 | 0.010 | 0.80 | 17.5-18.5 | 19.5-20.5 | 6.0-6.5 | |
| S31725 | 0.030 | 2.00 | 0.045 | 0.030 | 0.75 | 13.5-17.5 | 18.0-20.0 | 4.0-5.0 | |
| S31726 | 0.030 | 2.00 | 0.045 | 0.030 | 0.75 | 13.5-17.5 | 17.0-20.0 | 4.0-5.0 | |
| S34565 | 0.030 | 5.0-7.0 | 0.030 | 0.010 | 1.00 | 16.0-18.0 | 23.0-25.0 | 4.0-5.0 | |
| S33228 | 0.004-0.008 | 1.0 | 0.020 | 0.015 | 0.30 | 31.0-33.0 | 26.0-28.0 | - |
Mechanical Properties of ASTM A403
| Grade | UNS | Tensile Strength, min | Yield Strength,min | Elongation min % in 4D | |||
| ksi | MPa | ksi | MPa | Longit % | Trans% | ||
| ALL | ALL | 75 | 515 | 30 | 205 | 28 | 20 |
| 304L | S30403 | 70 | 485 | 25 | 170 | 28 | 20 |
| 316L | S31603 | 70 | 485 | 25 | 170 | 28 | 20 |
| 304N | S30451 | 80 | 550 | 35 | 240 | 28 | 20 |
| 316N | S31651 | 80 | 550 | 35 | 240 | 28 | 20 |
| S31726 | 80 | 550 | 35 | 240 | 28 | 20 | |
| XM-19 | S20910 | 100 | 690 | 55 | 380 | 28 | 20 |
| S31254 | 94-119 | 650-820 | 44 | 300 | 28 | 20 | |
| S34565 | 115 | 795 | 60 | 415 | 28 | 20 | |
| S33228 | 73 | 500 | 27 | 185 | 28 | 20 | |
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