Is 2101 cheaper than 316L?

By weight, often yes, and above all less exposed to the nickel price. On the finished item, the gain depends entirely on the ability to reduce wall thickness: that is a design calculation, not a purchasing one.

What is the difference from 2304?

Both reach a similar PREN by different routes. 2101 relies on nitrogen and manganese with very little nickel; 2304 relies on higher chromium, 21.5 to 24.5%, with 3 to 5.5% nickel. 2101 is the more nickel-frugal of the two.

Does it weld like a 2205?

The same principles apply — controlled heat input, over-alloyed filler, phase balance to watch. Its low nickel content makes that balance even more sensitive to rapid cooling on thin sections.

GRADE PROFILE

2101 — S32101 / X2CrMnNiN21-5-1

2101 is a lean duplex: 21% chromium, but only 1.35 to 1.70% nickel, replaced by manganese and nitrogen. PREN comparable to a 316L, duplex strength, and far less exposure to the nickel market.

Duplex
PREN 24–29
Cost index 80

When to choose it

On storage tanks and vessels, chemical transport tanks, water treatment, and cooking liquors in pulp and paper. Wherever the design can exploit the yield strength to reduce wall thickness, 2101 replaces a 304L or 316L with a favourable material balance.

It is also the grade to consider when exposure to the nickel price is a management issue: at 1.5% nickel against 10 to 13% for a 316L, the volatility of material cost changes in nature.

When not to choose it

As an automatic substitute for 316L at unchanged geometry. The PREN is comparable, so corrosion resistance is too: the entire gain is mechanical, and it disappears if the wall thickness does not change. Substituting without revisiting the design means changing grade for nothing.

In hot seawater and heavily chlorinated media: step up to 2205 or 2507.

Above 250 °C, where embrittlement threatens as with every duplex, at an even lower threshold.

In heavy cold forming. A lean duplex demands markedly higher forces than an austenitic, and tooling sized for 304L will not follow.

Composition

Chemical composition (% by mass)
Element	%
C	≤ 0.04
Mn	4–6
P	≤ 0.04
S	≤ 0.03
Si	≤ 1
Ni	1.35–1.7
Cr	21–22
Mo	0.1–0.8
N	0.2–0.25
Cu	0.1–0.8

Mechanical properties

Mechanical properties
Standard	Form	Rm (MPa)	Rp0.2 (MPa)	A (%)	Hardness
ASTM A789/A789M tableau 4	tube, épaisseur ≤ 5,00 mm	≥ 700	≥ 530	≥ 30	≤ 290 HBW
ASTM A789/A789M tableau 4	tube, épaisseur > 5,00 mm	≥ 650	≥ 450	≥ 30	≤ 290 HBW

Designations and standards

Equivalent normative designations
Reference	Designation
EN (numeric)	1.4162
EN (symbolic)	X2CrMnNiN21-5-1
ASTM / AISI	2101
UNS	S32101
JIS	—
AFNOR	—

Tube product standards :

ASTM A789/A789M
ASTM A790/A790M
ASTM A240 (produits plats)

Availability

Available in welded and seamless tube to ASTM A789 and A790. Structured dimensional data for this grade is not yet documented in our reference set: send us your sizes. EN 10204 3.1 material certificates supplied with the goods.

Related grades

2304 (S32304) — the other lean duplex, at equivalent PREN, reached through chromium rather than nitrogen and manganese.
2205 (1.4462) — the step up as soon as chlorides rise.
316L (1.4404) — the austenitic reference to compare against, PREN for PREN.

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Frequently asked questions

Is 2101 cheaper than 316L?: By weight, often yes, and above all less exposed to the nickel price. On the finished item, the gain depends entirely on the ability to reduce wall thickness: that is a design calculation, not a purchasing one.
What is the difference from 2304?: Both reach a similar PREN by different routes. 2101 relies on nitrogen and manganese with very little nickel; 2304 relies on higher chromium, 21.5 to 24.5%, with 3 to 5.5% nickel. 2101 is the more nickel-frugal of the two.
Does it weld like a 2205?: The same principles apply — controlled heat input, over-alloyed filler, phase balance to watch. Its low nickel content makes that balance even more sensitive to rapid cooling on thin sections.