This specification2 covers nominal-wall-thickness welded tubes and heavily cold worked welded tubes made from the austenitic steels listed in Table 1, with various grades intended for such use as boiler, superheater, heat exchanger, or condenser tubes.Grades TP304H, TP309H, TP309HCb, TP310H, TP310HCb, TP316H, TP321H, TP347H, and TP348H are modifications of Grades TP304, TP309S, TP309Cb, TP310S, TP310Cb, TP316, TP321, TP347, and TP348, and are intended for high-temperature service such as for superheaters and reheaters.The tubing sizes and thicknesses usually furnished to this specification are 1⁄8 in. [3.2 mm] in inside diameter to 12 in. [304.8 mm] in outside diameter and 0.015 to 0.320 in. [0.4 to 8.1 mm], inclusive, in wall thickness. Tubing having other dimensions may be furnished, provided such tubes comply with all other requirements of this specification. Mechanical property requirements do not apply to tubing smaller than 1⁄8 in. [3.2 mm] in inside diameter or 0.015 in. [0.4 mm] in thickness.Optional supplementary requirements are provided and, when one or more of these are desired, each shall be so stated in the order.
| Grades | UNS Designation |
|---|---|
| TP201 | S20100 |
| TP 201LN | S20153 |
| TP202 | S20200 |
| TPXM-19 | S20910 |
| TPXM-29 | S24000 |
| TP304 | S30400 |
| TP304L | S30403 |
| TP304H | S30409 |
| - | S30415 |
| TP304N | S30451 |
| TP304LN | S30453 |
| TP305 | S30500 |
| - | S30615 |
| - | S30815 |
| TP309S | S30908 |
| TP309H | S30909 |
| TP309Cb | S30940 |
| TP309HCb | S30941 |
| TP310S | S31008 |
| TP310H | S31009 |
| TP310Cb | S31040 |
| TP310HCb | S31041 |
| - | S31050 |
| - | S31254 |
| - | S31277 |
| TP316 | S31600 |
| TP316L | S31603 |
| TP316H | S31609 |
| TP316N | S31651 |
| TP316LN | S31653 |
| TP317 | S31700 |
| TP317L | S31703 |
| - | S31725 |
| - | S31726 |
| - | S31727 |
| - | S32050 |
| - | S32053 |
| TP321 | S32100 |
| TP321H | S32109 |
| - | S32654 |
| - | S33228 |
| - | S34565 |
| TP347 | S34700 |
| TP347H | S34709 |
| TP348 | S34800 |
| TP348H | S34809 |
| - | S35045 |
| TPXM-15 | S38100 |
| - | S38815 |
| - | N08367 |
| - | N08904 |
| - | N08926 |