EN 10088-2 X1CrNi25-21 1.4335 Stainless Steel Plate

EN 10088-2 X1CrNi25-21 1.4335 stainless steel plate is a high-alloy austenitic flat product supplied to EN 10088-2, the European standard for stainless steel sheet, plate and strip for general purposes. X1CrNi25-21 contains up to 0.020 % carbon, 0.25 % silicon, 0.20 % molybdenum and 0.10 % nitrogen, with 24.0 – 26.0 % chromium and 20.0 – 22.0 % nickel. It is a low-carbon, low-silicon version of the 25Cr-20Ni composition of 310S, made for nitric acid service. EN 10088-2 places 1.4335 among its special grades, defined as grades for special use and/or with limited availability, and Table 7 lists it as hot rolled plate (P) up to 75 mm only, solution annealed. Table 7 rates it resistant to intergranular corrosion both as delivered and after sensitization.

SHH STEEL works as a steel sourcing partner with long-term relationships with Chinese stainless mills that roll high-alloy austenitic hot rolled plate. For large tonnages, the buyer can contract directly with a suitable mill, with SHH STEEL assisting for a modest service fee and handling follow-up and documents. For small orders we consolidate demand, so that 1 – 5 t lots are placed against genuine mill production instead of stock of unknown origin. Each shipment can be released after third-party inspection by TUV, ABS, BV, DNV, CCS or an agency the buyer nominates, and payment by TT or LC is accepted. The rest of this page covers the technical side of EN 10088-2 1.4335 and the steps we take so that the sheet that arrives is the sheet that was ordered.

The table below lists the concerns buyers raise most often when sourcing EN 10088-2 X1CrNi25-21 sheet and plate from China, and how SHH STEEL deals with each of them.

1.4335 is often called 310L, or 310L NAG (nitric acid grade), and is sometimes given the number UNS S31002, but ASTM A240-22 lists no such grade; its 310-type entries start with S31008 (310S). The composition is also sold as UR 65 by ArcelorMittal Industeel; UR is an Industeel trademark, and a specific producer’s branded product has to be named and agreed in the order. SHH STEEL orders and certifies by EN steel number. For pressure equipment the grade is ordered to EN 10028-7; see EN 10028-7 1.4335 pressure vessel plate.

The table shows why ASTM A240 Type 310S stainless steel plate is not an equivalent: chromium and nickel overlap, but 310S allows four times the carbon and six times the silicon. This is the key point in any 1.4335 nitric acid enquiry. A 1.4335 heat can normally be certified as S31008 as well, since it falls inside the 310S limits, but a 310S heat cannot be certified as 1.4335. SHH STEEL therefore orders nitric acid plate by EN number, not as 310S.

1.4335 is also listed in EN 10028-7 for pressure purposes. That standard may set its own test and property requirements, which we have not reproduced here.

Edition note: the values on this page are taken from EN 10088-2:2014. A revised edition (EN 10088-2:2024) has since been published. If your contract names the newer edition, SHH STEEL checks the order against that text before production, and any difference is raised at the quotation stage rather than after rolling.

The 1.4335 chemical composition below is the cast (heat) analysis from EN 10088-2:2014 Table 1. Values are percentages by mass; a single figure is a maximum.

The 1.4335 chemical composition limits carbon to 0.020 % and silicon to 0.25 %, with molybdenum capped at 0.20 %. Those limits matter as much as the chromium and nickel ranges for nitric acid service. SHH STEEL checks carbon and silicon on every certificate as part of the 1.4335 chemical composition review.

Product analysis tolerances (EN 10088-2 Table 5)

A product analysis is a check made on the delivered sheet. It is not mandatory under EN 10088-2; it is carried out when agreed at the time of enquiry and order, and SHH STEEL can arrange it through a partner laboratory. The permissible tolerances on the cast limits are:

Where several product analyses are made on one cast, individual results may exceed the maximum or fall below the minimum, but not both for the same element. Nickel uses ± 0.15 % at the 20.0 % minimum and ± 0.20 % at the 22.0 % maximum, because Table 5 changes band at 20 %. If a product analysis is required, it should be stated in the order together with the Table 5 tolerances.

The 1.4335 mechanical properties below are the room-temperature values from EN 10088-2:2014 Table 7 for austenitic steels in the solution annealed condition. Test pieces are transverse; the A80 elongation applies below 3 mm and the proportional elongation A from 3 mm.

Rp1.0 values are for guidance only. For bigger sizes than those listed, mechanical values are to be agreed at the time of enquiry and order.

EN 10088-2 lists 1.4335 as hot rolled plate only. Table 7 rates its resistance to intergranular corrosion (EN ISO 3651-2) as “yes” in both the delivery condition and the sensitized condition.

Cold worked condition (process route 2H)

EN 10088-2 Tables 19 and 20 list no cold worked (2H) strength levels for 1.4335, so the grade is ordered in the solution annealed condition (+AT).

Minimum proof strength at elevated temperature (EN 10088-2 Table 12, +AT)

EN 10088-2 Table 12 gives values for 1.4335 from 100 °C to 400 °C, for the solution annealed condition (+AT). They are minimum values for design and are not tested unless agreed.

EN 10088-2 Table A.1 gives the following guideline temperatures for 1.4335:

The footnotes to Table A.1 state that with a continuous furnace the upper part of the range is usually preferred or even exceeded, and that the lower end of the range should be aimed at when the heat treatment is part of further processing, because otherwise the mechanical properties may be affected. Solution annealing may be omitted if hot working and cooling achieve the required mechanical properties and resistance to intergranular corrosion.

The Euro Inox tables give the same 1 030 – 1 110 °C range with cooling in air or water. Plate is delivered as +AT.

The values below are approximate reference figures for X1CrNi25-21 at room temperature, from the worldstainless “Tables of Technical Properties”, which follow EN 10088-1. They are suitable for design estimates and weight calculation; where a figure is critical, use EN 10088-1 itself.

The worldstainless table gives 1.4335 a density of 7.9 g/cm³, a modulus of 195 GPa, a thermal conductivity of 14 W/(m·K), a specific heat of 450 J/(kg·K) and an electrical resistivity of 0.85 Ω·mm²/m. 1.4335 is not listed in the EN 10088-1 extract by Häuselmann that we use for magnetic behaviour, so the magnetic statement above is the general austenitic one.

ArcelorMittal Industeel’s UR 65 datasheet describes the 310L NAG composition, certified to EN 1.4335, for nitric acid service, including boiling nitric acid of 50 – 65 % and concentrations up to 70 %, but not for media containing hexavalent chromium (Cr VI). The Applus+ materials portal lists 1.4335 for oxidizing acids, especially nitric acid up to 70 % at increased temperature, with resistance to intergranular corrosion also in the sensitized condition. EN 10088-2 Table 7 rates its resistance to intergranular corrosion, tested to EN ISO 3651-2, as “yes” in the delivery condition and “yes” in the sensitized condition.

For milder nitric acid duties, EN 10088-2 1.4306 plate is the usual low-carbon 18-10 comparison; the Euro Inox tables credit it with good resistance to nitric acid of higher concentration and temperature.

Corrosion resistance depends on the actual medium, its impurities and its temperature, so service experience or tests in the real medium should guide grade selection.

1.4335 is weldable by the common arc and resistance processes. As a fully austenitic grade, it needs a filler and procedure that keep the weld metal fit for nitric acid.

• The Euro Inox fabrication tables rate TIG/MIG, manual metal arc, resistance and autogenous welding as suitable for 1.4335.
• The filler material listed is 1.4466; the plate form of that grade is EN 10028-7 1.4466 plate.
• EN 10088-2 Table 7 rates 1.4335 “yes” for intergranular corrosion after sensitization.
• EN 10088-2 does not specify welding procedures; these are published guidelines and general practice.

These points reflect industry practice for high-alloy austenitic stainless steels rather than requirements of EN 10088-2, which does not specify welding procedures. In the SHH STEEL workshop, plate blanks are cut with clean, burr-free edges, ready for the fabricator’s own joint preparation.

Annealed 1.4335 plate forms with standard austenitic practice; with a proof strength of 200 MPa and 40 % elongation, it bends and rolls readily.

Plate is cut by plasma or waterjet, or sawn. Machining needs sharp tools, rigid set-ups and positive feeds to avoid work hardening at the cut.

We run our own workshop next to the warehouse, so 1.4335 hot rolled plate and X1CrNi25-21 plate blanks can be delivered cut to size or bent. Details are on our steel cutting services and bending and forming services pages.

EN 10088-2 Table 7 lists 1.4335 only as hot rolled plate (P) up to 75 mm.

For bigger sizes than those listed, the mechanical values shall be agreed at the time of enquiry and order. Under section 6.9 of the standard, EN ISO 18286 applies to individually rolled quarto plate.

SHH STEEL can supply 1.4335 hot rolled plate in standard sizes or cut to your drawing, after confirming availability with the mill; sheet and strip have to be agreed separately.

Surface finish is ordered by the process route symbols of EN 10088-2 Table 6; trade names from ASTM and JIS are shown for reference. Not every route is available for every grade, and the mill confirms which ones it can supply.

EN 10088-2 Table 7 lists this grade as hot rolled plate (P) only, so the cold rolled routes 2D, 2B and 2R are not part of the standard offer and would have to be agreed separately. The No.1 cross-reference follows worldstainless and IMOA comparison tables.

There is no exact 1.4335 equivalent in ASTM A240, JIS G4305 or GB/T 4237. The trade names 310L and 310L NAG describe the same idea, and the nearest standard grades are the 310S family.

All three nearest grades share the 25Cr-20Ni base, but none sets the low carbon and silicon limits of 1.4335. They can be used where nitric acid resistance is not the reason for the grade; otherwise, the order should name 1.4335.

1.4335 vs 310S

On 1.4335 vs 310S: both have 24.0 – 26.0 % chromium and about 20 % nickel, but 1.4335 limits carbon to 0.020 % and silicon to 0.25 %, against 0.08 % and 1.50 % for ASTM S31008. Low carbon protects against chromium carbide precipitation in welds, and the much tighter silicon limit is part of what separates the nitric acid grade from the heat-resistant 310S. Both are rated resistant to intergranular corrosion after sensitization in EN 10088-2 Table 7.

Typical applications of 1.4335 plate given by Industeel and the Applus+ materials portal include:

• Nitric acid production plant
• Ammonium nitrate and other fertilizer plant
• Urea synthesis equipment
• Nuclear fuel reprocessing
• Hydrofluoric acid pickling equipment

For pressure equipment, 1.4335 plate is ordered to EN 10028-7; for other uses, EN 10088-2 applies.

SHH STEEL can advise when 1.4306 or a higher-alloyed grade should be compared for a given acid concentration and temperature.

For 1.4335 the main risks are 310S material supplied as 310L, carbon or silicon above the EN limits, use in media containing hexavalent chromium, and the plate-only listing in EN 10088-2.

None of these steps is complicated, but they need to be agreed at the start. When you send an enquiry, tell us which of these points matters most to you, and the order will be built around it.

Every 1.4335 order is supported by documents and checks that make the material traceable to the heat:

• Cast analysis with carbon, silicon, chromium and nickel checked
• Tensile test (transverse) to Table 7
• Impact test for plate over 10 mm when agreed
• Intergranular corrosion test to EN ISO 3651-2 when agreed
• Thickness, flatness and surface inspection
• Additional checks through our third-party testing service: PMI, dimensional, flatness and surface inspection

If the order does not name an inspection document, EN 10088-2 requires only a test report 2.2. Because this is rarely enough for nitric acid, fertilizer and urea plant equipment or export work, SHH STEEL supplies an EN 10204 3.1 inspection certificate as standard and a 3.2 certificate when an independent inspector (TUV, ABS, BV, DNV, CCS or an agency you nominate) witnesses testing and countersigns the document.

Ordering example and lead time

Following the pattern of the example in EN 10088-2, a typical order line would read: 4 plates, 12 mm × 1 500 mm × 6 000 mm, EN ISO 18286, EN 10088-2, steel X1CrNi25-21 (1.4335), process route 1D, inspection certificate 3.1 to EN 10204. Mill production lead time is generally 30 – 40 days from order confirmation, depending on the rolling schedule, the size and the tests requested; because 1.4335 is a special grade, the campaign date should be confirmed at enquiry. Consolidated small lots follow the same mill schedule, and we send progress updates at rolling, testing and packing.

• Mill relationships: long-term cooperation with Chinese stainless mills helps us secure competitive pricing and steadier delivery for 1.4335 and related high-alloy austenitic grades.
• Direct mill contracts: for larger tonnages you can contract directly with a suitable mill, for a modest service fee, while we handle follow-up and documents.
• Order consolidation: 1 – 5 t lots are combined so they can be placed against genuine mill production.
• Own workshop: slitting, cut-to-length, laser cutting, bending and protective film before shipment.
• Inspection and certificates: third-party inspection by TUV, ABS, BV, DNV, CCS or your nominated agency, with EN 10204 3.1 or 3.2 certificates.
• Flexible payment: TT, LC or a combination of both.
• Port logistics: coil and sheet are packed seaworthy with heat-number labels and shipped through our worldwide shipping service, together with other grades if needed.

As a 1.4335 plate supplier SHH STEEL also stocks and sources the wider range of stainless steel sheets and plates, so mixed orders of different stainless grades can travel in one container with one set of paperwork.

EN 10088-2 X1CrNi25-21 1.4335 is the low-carbon, low-silicon 25Cr-21Ni austenitic special grade of the 310L type, supplied as hot rolled plate up to 75 mm for nitric acid and fertilizer plant equipment. Choosing it is the easy part. Getting genuine material that matches the certificate, in the gauge and finish your parts need and on a predictable schedule, is where a sourcing partner earns its place, and that is the work SHH STEEL does every day through long-term mill cooperation, consolidation and its own workshop.

The next step is simple. Send SHH STEEL your drawing, or an enquiry with the quantity, thickness, width, finish and delivery destination, and we will judge whether a direct mill contract or consolidation with processing fits your order better, and quote accordingly. Send your sizes and quantities for a quotation.