What is the difference between EN 1.4432 and EN 1.4404 (both called 316L)?

Both 1.4432 and 1.4404 are 316L (low carbon, C ≤ 0.030%), but they differ in molybdenum content. EN 1.4404 specifies Mo 2.0–2.5%; EN 1.4432 specifies Mo 2.5–3.0%. The higher Mo in 1.4432 increases the PRE from approximately 24 to approximately 26, giving better resistance to chloride pitting and crevice corrosion. However, ASTM A403 WP316L covers both Mo ranges — so a WP316L certificate alone could be either grade. For European projects requiring the higher Mo, you must specify 1.4432 explicitly by Werkstoffnummer.

EN 10253-2 Type B PRE ~26 Mo 2.5–3.0% Must Specify 1.4432 Explicitly

EN 1.4432 (316L High Mo) Pipe Fittings

X2CrNiMo17-12-3 · Mo 2.5–3.0% · PRE ~26

316L with higher molybdenum (2.5–3.0% vs 2.0–2.5% for standard 1.4404), giving PRE ~26 — marginally better chloride pitting resistance than standard 316L. Critical: ASTM A403 WP316L covers both the 1.4404 and 1.4432 Mo ranges — "WP316L" alone does not guarantee the higher Mo. For European projects requiring 1.4432, specify by W.Nr. on the purchase order and verify Mo on the test certificate.

Grade Designations

System	Designation
EN Werkstoffnummer	1.4432
EN Grade Name	X2CrNiMo17-12-3
ASTM	A403 WP316L (covers BOTH 1.4404 and 1.4432 Mo ranges)
Note	Specify 1.4432 explicitly — "WP316L" alone is insufficient

1.4404 vs 1.4432 — The Mo Difference

Parameter	1.4404 (316L standard)	1.4432 (316L high Mo)
EN Grade Name	X2CrNiMo17-12-2	X2CrNiMo17-12-3
Mo	2.0–2.5%	2.5–3.0%
PRE (approx.)	~24	~26
C (both low-carbon)	≤0.030%	≤0.030%
Cr, Ni, N	Same	Same
ASTM WP316L covers?	Yes — both covered	Yes — but not distinguishable from WP316L cert alone

When to Specify 1.4432 Instead of 1.4404

The PRE difference between 1.4404 (~24) and 1.4432 (~26) is real but modest. Specify 1.4432 when:

• Chloride levels are at the upper end of 316L's acceptable range — the extra Mo buys margin
• The specification or project standard explicitly calls for 1.4432 or "316L Mo 2.5% min"
• Operating temperature combined with chloride is close to 316L's pitting threshold
• Coastal or mildly marine environments where standard 316L is marginal

For significant chloride service (seawater, offshore, produced water), the jump to Duplex 2205 (1.4462, PRE ≥35) is more meaningful than 1.4432's incremental uplift over 1.4404.

316 Family — Complete Grade Comparison

W.Nr.	Grade	Mo	PRE	Specify When
1.4401	316	2.0–2.5%	~24	Non-welded; dual-cert to 316L preferred
1.4404 ★	316L	2.0–2.5%	~24	Standard welded SS — most common specification
1.4571 ★	316Ti	2.0–2.5%	~24	Germany/Italy/CE Europe convention
1.4432	316L Hi-Mo	2.5–3.0%	~26	Moderate chloride uplift; explicit specification needed
1.4435	316L Nuclear	2.5–3.0%	~26	Ni 12.5–15%; FN≤1; nuclear/pharma/fatigue
1.4462	Duplex 2205	3.0–3.5%	≥35	Seawater, offshore — significant chloride upgrade

EN 1.4432

316L High Mo / X2CrNiMo17-12-3

PRE:~26

Mo:2.5–3.0%

C max:0.030% (Low)

vs 1.4404:+0.5% Mo, PRE +2

Request 1.4432 Quote

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