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- ISO 9001 - 2015 Certified
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- NACE MR0175 / ISO 15156-2
- NORSOK M-650 Qualified
- API 6A Certified
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- MERKBLATT AD 2000 W2/W7/W10
EN 10088-3 Super Duplex 2507 (Werkstoff 1.4410 / X2CrNiMoN25-7-4)
EN 10088-3 is the European technical delivery condition for semi-finished products, bars, rods, wire, sections, and bright products of stainless steel for general purposes. Within EN 10088-3, super duplex 2507 is registered as Werkstoff 1.4410 with the EN-format name X2CrNiMoN25-7-4. The X prefix indicates a high-alloy steel; the digits decode to nominal 25 percent chromium, 7 percent nickel, 4 percent (rounded from 3.5) molybdenum, with intentional nitrogen addition.
Continental European and Norwegian buyers commonly specify on the EN designation rather than the UNS S32750 / ASTM equivalent. TorqBolt cross-references EN to ASTM on every supply and includes both designations in the mill test certificate.
EN 10088-3 Scope
EN 10088-3 covers semi-finished products, bars, rods, wire, sections, and bright products of stainless steel for general purposes. The standard governs chemistry, mechanical properties, surface conditions, and dimensional tolerances. EN 10088-1 carries the parent chemistry table; EN 10088-2 covers sheet, plate, and strip; EN 10088-3 covers bars, rods, sections, and wire. EN 10088-4 and -5 extend the family to construction-purpose products.
Werkstoff 1.4410 / X2CrNiMoN25-7-4 Decoded
| Element of designation | Meaning |
|---|---|
| X | High-alloy steel (sum of alloying elements above 5 percent) |
| 2 | Carbon content x 100 (max 0.030 percent, designation rounds to 2) |
| Cr 25 | Nominal chromium content (24-26 percent actual) |
| Ni 7 | Nominal nickel content (6-8 percent actual) |
| Mo 4 | Nominal molybdenum content (3-5 percent actual, rounded up to 4 in name) |
| N | Intentional nitrogen addition (0.24-0.32 percent) |
| 1.4410 (Werkstoff Nummer) | European material number, equivalent to UNS S32750 |
EN 10088-3 Chemistry for 1.4410
| Element | EN 10088-3 Min % | EN 10088-3 Max % |
|---|---|---|
| Carbon (C) | (no min) | 0.030 |
| Chromium (Cr) | 24.0 | 26.0 |
| Nickel (Ni) | 6.0 | 8.0 |
| Molybdenum (Mo) | 3.0 | 5.0 |
| Nitrogen (N) | 0.24 | 0.32 |
| Manganese (Mn) | (no min) | 2.00 |
| Silicon (Si) | (no min) | 1.00 |
| Phosphorus (P) | (no min) | 0.035 |
| Sulfur (S) | (no min) | 0.015 |
EN 10088-3 Mechanical Properties (1.4410, Solution Annealed)
| Property | Minimum |
|---|---|
| Yield strength Rp0.2 | 530 MPa |
| Tensile strength Rm | 730 to 930 MPa |
| Elongation A5 | 20 percent |
| Hardness | 290 HBW max |
| Charpy V-notch at 20 °C | 100 J longitudinal, 60 J transverse |
Note: EN 10088-3 yield (530 MPa) is slightly lower than ASTM A479 (550 MPa). The difference reflects test method conventions; mill heats routinely meet both windows.
Related EN Standards
- EN 10088-1: parent chemistry table for stainless steels
- EN 10088-2: sheet, plate, and strip
- EN 10088-3: bars, rods, sections, wire (this standard)
- EN 10088-4 / -5: construction-purpose stainless products
- EN 10216-5: seamless tubes for pressure purposes
- EN 10217-7: welded tubes for pressure purposes
- EN 10222-5: forgings for pressure purposes
- EN 10272: bars for pressure purposes
EN 10088-3 / 1.4410 Cross-Reference to ASTM and UNS
| System | Designation |
|---|---|
| EN 10088-3 (Werkstoff Nummer) | 1.4410 |
| EN 10088-3 (name) | X2CrNiMoN25-7-4 |
| UNS | S32750 |
| ASTM bar | A479 UNS S32750 |
| ASTM forgings | A182 F53 |
| ASTM pipe | A790 UNS S32750 |
| NORSOK MDS | M-630 D55, D57 |
| Common name | Super Duplex 2507 |
| Sandvik trademark | SAF 2507 |
| Industeel trademark | UR 52N+ |
| Outokumpu trademark | Avesta 2507 |
EN 10088-3 / 1.4410 Products from TorqBolt
- Round bar per EN 10088-3 / EN 10272
- Bar stock hex, flat, square sections per EN 10088-3
- Wire and welding wire per EN 10088-3
- Pipe per EN 10216-5 (seamless) and EN 10217-7 (welded)
- Tube per EN 10216-5
- Forgings per EN 10222-5
- Flanges per EN 1092-1 (dimensions) in 1.4410 chemistry
- Fittings per EN 10253-4
- Fasteners in 1.4410 chemistry per ASTM A1082 (no dedicated EN fastener spec for super duplex)
EN 10088-3 / 1.4410 FAQ
Is Werkstoff 1.4410 the same as UNS S32750?
Yes. Both designations refer to the same super duplex stainless steel chemistry within negligible tolerance. The American UNS system uses S32750; the European EN 10088 system uses 1.4410 (Werkstoff Nummer) with the EN name X2CrNiMoN25-7-4. Mill certificates routinely cite both.
What does the X2CrNiMoN25-7-4 name mean?
X = high-alloy steel; 2 = carbon × 100 (max 0.030 percent rounds to 2); Cr 25, Ni 7, Mo 4 = nominal chromium, nickel, molybdenum percentages; N = intentional nitrogen addition (0.24-0.32 percent). The chemistry window mirrors UNS S32750 / ASTM A479 within rounding tolerance.
Which EN standards apply to super duplex 2507 product forms?
EN 10088-3 (bars, rods, sections, wire), EN 10088-2 (sheet, plate, strip), EN 10216-5 (seamless tube for pressure), EN 10217-7 (welded tube for pressure), EN 10222-5 (forgings for pressure), EN 10272 (bars for pressure), EN 1092-1 (flange dimensions), EN 10253-4 (fittings dimensions). Material chemistry remains 1.4410 across all forms.
What is the difference between EN 10088-3 mechanical properties and ASTM A479 for the same alloy?
EN 10088-3 specifies yield Rp0.2 ≥ 530 MPa; ASTM A479 specifies yield ≥ 550 MPa. The difference reflects test method conventions and rounding. Tensile strengths (730-930 MPa per EN; ≥ 795 MPa per ASTM) overlap at the production heat level. Mill heats routinely meet both windows simultaneously.
What hardness limit applies to 1.4410 for sour service?
EN 10088-3 caps hardness at 290 HBW. For sour service per NACE MR0175 / ISO 15156-3, hardness must be 28 HRC maximum (more restrictive than the EN limit). The NACE limit governs when both apply simultaneously.
Where is Werkstoff 1.4410 specified?
Continental European, Scandinavian, and Norwegian Continental Shelf (NCS) projects. NORSOK M-630 references EN designations alongside ASTM. Many German chemical-plant specifications and TÜV-witnessed supplies require the 1.4410 designation explicitly even when ASTM A479 chemistry is delivered.
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