321/321H Stainless Steel Seamless Pipe & Tube
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What kind of steel is 1.4541?
AISI 321 (1.4541) is an austenitic chromium-nickel stainless steel stabilized with titanium. Its base chemistry is close to 304, but titanium ties up carbon as stable titanium carbides. Chromium therefore stays in solid solution, and the material keeps its resistance to intergranular corrosion both after welding and during long service at temperatures where ordinary 18/8 steel becomes sensitized. The short answer to “what is 1.4541?”: a stainless, but not acid-resistant grade (it contains no molybdenum), designed mainly for welded structures and high-temperature service. The Russian equivalent is 08X18H10T, which also appears in tube descriptions as 08Cr18Ni10T.
1.4541 / 1.4878 / 321 / 321H in tube descriptions
Most tubes in this category carry four designations at once. 1.4878 (X8CrNiTi18-10) is the version from EN 10095 for heat-resistant steels, with a higher permitted carbon content, while 321H is the American variant of 321 with carbon in the 0.04–0.10% range, which improves strength at elevated temperatures. The mill melts material that falls within the limits of all these grades and marks the tube with each of them, so the same tube suits both a standard system and equipment designed for elevated temperatures. Other variants – plain “1.4541”, “1.4541 / 321”, “TP321 / TP321H” or GOST designations – describe the same type of steel in other systems. We explain how to read them in our article Stainless steel designations: AISI, EN, DIN, GOST. The grade of each heat is confirmed by an EN 10204 3.1 certificate.
Chemical composition of 1.4541 and 1.4878
| Grade | C | Cr | Ni | Ti |
|---|---|---|---|---|
| 1.4541 / 321 | ≤ 0.08 | 17.0–19.0 | 9.0–12.0 | 5×C – 0.70 |
| 1.4878 / 321H | ≤ 0.10 | 17.0–19.0 | 9.0–12.0 | 5×C – 0.80 |
Composition of 1.4541 per EN 10088-1, 1.4878 per EN 10095 (wt. %). Equivalents: 1.4541 = X6CrNiTi18-10 = AISI 321 = UNS S32100 = GOST 08X18H10T · 1.4878 = X8CrNiTi18-10 ≈ AISI 321H (UNS S32109).
Sizes from 6 mm tubing to DN 500
This is the widest diameter range among our grade-specific tube categories: 6 to 457.2 mm OD (DN 6–500), with walls from 0.5 to 47 mm. Alongside process pipe there is thin-wall instrument tubing and a small selection of heavy-wall hollow bar. Seamless 321 and 321H tube is produced to EN 10216-5 and ASTM A312 and A213, while material marked to GOST is made to GOST 9940 (hot-rolled tube) and GOST 9941 (cold-drawn tube). Any tube can be cut to length, and permissible OD and wall deviations are listed on our tube dimensional tolerances page.
Applications of 1.4541 and 321H pipe and tube
Stabilized 321 is chosen where welding meets heat: exhaust manifolds and lines, mufflers, bellows expansion joints, superheaters and steam piping, heat exchangers in power generation and petrochemicals, and aerospace. 1.4878 / 321H tube is specified for systems designed for long-term service at elevated temperatures, where creep resistance matters. The difference between oxidation resistance and high-temperature strength is explained in our article Heat-resistant vs. creep-resistant steel: the differences.
321 vs. 316Ti vs. 304
The closest relative of 1.4541 is 1.4571 – also titanium-stabilized, but with 2.0–2.5% molybdenum added. If the medium contains chlorides or acids, 316Ti / 1.4571 seamless tube or its low-carbon alternative, 316L seamless tube, is the better option. In systems operating at ambient temperature, titanium stabilization is not needed and 304 / 304L stainless tube is usually sufficient. For continuous service in hot gases above about 850°C, scaling resistance is what counts, so 1.4841 / 1.4845 heat-resistant tube is used. Under high stress in cold chloride solutions, duplex and super duplex tube has the edge.
See also: in the same grade we offer 1.4541 / 321 round bar. The full tube range, including other grades, is in our seamless tube and hollow bar category.