1.4301 vs. 1.4401 Stainless Steel Tubes: Composition, Properties and Applications

1.4301 (X5CrNi18-10) and 1.4401 (X5CrNiMo17-12-2) are the EN 10088 designations for the two most widely produced austenitic stainless steel tube grades. 1.4301 is the European equivalent of AISI 304; 1.4401 is the European equivalent of AISI 316. The single most important difference is molybdenum: 1.4401 contains 2.0-2.5% molybdenum, which changes its corrosion behavior in chloride and acid service. Both grades are fully austenitic, non-magnetic in the annealed condition and cannot be hardened by heat treatment.

Two EN Austenitic Tube Grades

The selection between 1.4301 and 1.4401 is rarely driven by mechanical performance, because the two grades are similar in strength and ductility. It is driven by corrosion resistance, cleaning chemistry and chloride exposure. 1.4301 is adequate for food contact, potable water and atmospheric service; 1.4401 is the minimum sensible choice wherever chlorides, seawater, dilute acids or repeated aggressive cleaning are involved.

Chemical Composition (EN 10088 Limits)

Element (wt%)	1.4301, X5CrNi18-10	1.4401, X5CrNiMo17-12-2
Carbon, max	0.07	0.07
Silicon, max	1.00	1.00
Manganese, max	2.00	2.00
Phosphorus, max	0.045	0.045
Sulfur, max	0.015	0.015
Chromium	17.5-19.5	16.5-18.5
Nickel	8.0-10.5	10.0-13.0
Molybdenum	-	2.0-2.5

Mechanical Properties (EN 10088-3, Solution Annealed, Minimum Values)

Property	1.4301	1.4401
0.2% proof strength, min (MPa)	190	200
Tensile strength (MPa)	500-700	500-700
Elongation, min (%)	45	40
Hardness, max	215 HB	215 HB

For seamless and welded tubes, EN 10216-5 and EN 10217-7 specify equivalent proof strength and tensile ranges for both grades. In practice the mechanical performance is similar, so the selection decision is driven by corrosion resistance.

Corrosion Resistance

Molybdenum stabilizes the passive film against localized attack. In seawater, chloride brines and chloride-bearing process media, 1.4401 resists pitting and crevice corrosion far better than 1.4301. 1.4301 will pit in chloride service, especially above about 60°C or where chlorides exceed roughly 200 ppm in the presence of crevices. PREN values, calculated as Cr + 3.3 x Mo + 16 x N, are typically around 19 for 1.4301 and around 25 for 1.4401 at mid-range composition.

Weldability, Applications and Cost

Both grades are welded by the same processes and consumable families. For tube welding, ER308L and ER316L filler metals per AWS A5.9 match 1.4301 and 1.4401 respectively, and autogenous orbital welding without filler is common for thin-wall instrument and dairy tubing. 1.4301 tubes serve food processing, brewing, dairy, architectural handrails and clean-media heat exchangers; 1.4401 tubes are specified for chemical plant, pharmaceutical utilities, marine equipment, pulp and paper, and any process with chlorides or dilute acids. In international quotations, 1.4401 tubes are typically priced 10-40% higher than equivalent 1.4301 tubes, a premium driven almost entirely by the molybdenum and higher nickel content, with the exact gap following ferro-molybdenum and nickel market prices.

FAQ

Q1. What is the difference between 1.4301 and 1.4401?

1.4401 contains 2.0-2.5% molybdenum and 10.0-13.0% nickel, giving it markedly better resistance to chlorides and pitting than 1.4301 (X5CrNi18-10).

Q2. Is 1.4301 the same as AISI 304?

Yes. 1.4301, X5CrNi18-10, corresponds to AISI 304 and JIS SUS304.

Q3. Is 1.4401 the same as AISI 316?

Yes. 1.4401, X5CrNiMo17-12-2, corresponds to AISI 316 and JIS SUS316; the low-carbon version is 1.4404, equivalent to 316L.

Q4. Which grade should be used for seawater?

1.4401 is the minimum reasonable choice for many marine applications; 1.4301 should not be used in chloride-rich or submerged marine service.

Q5. Why is 1.4401 more expensive?

The molybdenum addition and higher nickel content increase alloy cost, so market premiums of 10-40% over 1.4301 are common.

Q6. What are the Chinese equivalents of these grades?

Per GB/T 20878, 1.4301 corresponds to 06Cr19Ni10 (S30408) and 1.4401 to 06Cr17Ni12Mo2 (S31608).