Alloy steel forgings, technical datasheet

1.7335 forgings

Q: What is the ASTM equivalent of 1.7335 / 13CrMo4-5?

For forgings the closest ASTM equivalent is ASTM A182 Grade F12 Class 2 , or ASTM A336 Grade F12 for pressure-vessel forgings. In other product forms the equivalents are ASTM A387 Grade 12 Class 2 for plate, ASTM A335 Grade P12 for seamless pipe, ASTM A213 Grade T12 for tube and ASTM A234 Grade WP12 for fittings. All are the 1 % chromium, 0.5 % molybdenum family and share UNS K11562. The grades are close but not identical, so where a purchase order requires dual certification we issue a multi-designation mill certificate listing every specification the heat actually satisfies.

13CrMo4-5 / W.Nr. 1.7335 / old DIN 13CrMo44 / ASTM A182 F12 / A387 Gr.12 / P12 / T12 / GB 15CrMo / UNS K11562

1.7335 is the EN material number for 13CrMo4-5, a creep-resistant low-alloy steel with nominally 1 % chromium and 0.5 % molybdenum, used for pressure equipment operating at elevated temperature up to about 550 °C. Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory at No. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, forges 1.7335 into seamless rolled rings, discs, tubesheets, flanges, valve bodies, shafts, sleeves and bars to EN 10222-2 and ASTM A182 F12, supplied normalised and tempered with EN 10204 3.1 or 3.2 mill test certificates.

W.Nr.: 1.7335
EN name: 13CrMo4-5
Type: 1Cr-0.5Mo
Density: 7.85 g/cm³
Max service: ≈ 550 °C
Forge window: 850–1200 °C

Send a drawing for a quote Call 0086-189-2135-9659

0.70–1.15 %Chromium
0.40–0.60 %Molybdenum
450–600 MPaTensile, to 60 mm
300 MPaYield ReH, to 16 mm
15 tMax piece weight

Where 13CrMo4-5 lives on the temperature scale, 0 to 1250 °C

Process windows published by Jiangyin Jiangnan Metal Co., Ltd. Bar colours follow the heat tints carbon and low-alloy steel show in the forge. Values are the ranges we work to; the governing code or customer specification always takes precedence.

What is 1.7335?

1.7335 is the EN material number, also called the Werkstoff number, for the steel named 13CrMo4-5. It is a creep-resistant low-alloy steel carrying nominally 1 % chromium and 0.5 % molybdenum, with carbon held between 0.08 and 0.18 %. The old German designation for the same steel is 13CrMo44, and the same chemistry is sold in North America as ASTM Grade 12 material: F12 in forgings, P12 in pipe, T12 in tube and A387 Grade 12 in plate.

The two alloying elements do different jobs. Molybdenum is the one that matters most: it stays in solid solution and forms fine carbides that pin dislocations, and that is what stops the steel from creeping, or slowly stretching under load, at temperatures where plain carbon steel would fail in service. Chromium adds oxidation resistance, raises the tempering resistance, and, together with the molybdenum, gives the resistance to high-temperature hydrogen attack that makes this family standard in refineries.

The result is a steel that is deliberately not very strong at room temperature. Tensile strength is only 450 to 600 MPa in the normalised and tempered condition, well below a quenched and tempered grade such as 42CrMo4. That is the point. 13CrMo4-5 is chosen for what it does after ten years at 500 °C, not for what it does on the tensile machine on day one.

We supply 1.7335 as forged product only: open-die forgings and seamless rolled rings. Forging closes the porosity left by casting and aligns grain flow with the principal stress direction, which is why pressure-vessel codes treat a forged nozzle or tubesheet differently from a plate cut-out.

Why 13CrMo4-5 gets specified

Buyers reach for 1.7335 when the part will sit hot and pressurised for decades, and when plain carbon steel has run out of margin but a 9 % chromium grade would be overkill and hard to weld.

Creep strength to about 550 °C. The molybdenum carbides keep the creep rate low across the temperature band where most boiler, steam and refinery equipment actually operates.
Hydrogen service. 1Cr-0.5Mo is a recognised material on the API 941 Nelson curves, which set the temperature and hydrogen partial pressure combinations at which high-temperature hydrogen attack will not occur.
Weldable with ordinary shop practice. It needs preheat and post-weld heat treatment, but it welds with standard low-hydrogen B2-class consumables, unlike the 9Cr grades which need tight interpass control and a narrow PWHT band.
Cheap for what it does. Total alloy content is under 2 %, so the price sits close to carbon steel and far below stainless or nickel alloys for the same pressure duty.
Covered by every major code. EN, ASTM, ASME, JIS, GB and GOST all list an equivalent, so the same forging can usually be certified against whichever specification the end user's insurer recognises.
Machines and forms predictably. In the normalised and tempered condition the hardness is moderate and uniform, which keeps machining allowances small on large tubesheets and channel covers.

Where not to use it. 13CrMo4-5 has no useful corrosion resistance in wet or acidic service. It is a high-temperature steel, not a corrosion-resistant one. It should not be relied on above roughly 550 to 570 °C, where creep and long-term temper embrittlement take over; move to 10CrMo9-10 (1.7380) or a 9Cr-1Mo-V grade. For sour or chloride-bearing wet service, specify a stainless or nickel alloy such as Inconel 625.

International equivalent grades for 1.7335

Buyers reach this steel through at least a dozen different names. Every designation in the table below describes the same 1 % chromium, 0.5 % molybdenum chemistry. Jiangyin Jiangnan Metal Co., Ltd. accepts purchase orders under any of them and issues a multi-designation material test certificate listing every specification the heat actually satisfies.

Table 1. 13CrMo4-5 / 1.7335 equivalents by standards body and product form
Region / standard	Designation	Product form covered
EN 10027-2 (material number)	1.7335	All forms
EN 10027-1 (steel name)	13CrMo4-5	All forms
EN 10222-2	13CrMo4-5	Forgings for pressure purposes
EN 10028-2	13CrMo4-5	Plate for pressure purposes
EN 10216-2	13CrMo4-5	Seamless tube for pressure purposes
EN 10273	13CrMo4-5	Hot rolled weldable bar
DIN (superseded)	13CrMo44 (DIN 17175, DIN 17243)	Tube, forgings
ASTM / ASME (USA)	A182 F12 Cl.2, A336 F12	Forged flanges, fittings, vessel forgings
ASTM / ASME (USA)	A387 Gr.12 Cl.2	Pressure vessel plate
ASTM / ASME (USA)	A335 P12, A369 FP12	Seamless pipe
ASTM / ASME (USA)	A213 T12	Boiler and superheater tube
ASTM / ASME (USA)	A234 WP12	Wrought fittings
UNS	K11562	All forms
GB (China)	15CrMo (GB/T 3077); 15CrMoR (GB 713)	Structural and forging; vessel plate
JIS (Japan)	SCMV 2, STBA 22, SFVA F12	Plate, tube, forgings
AFNOR (France)	15CD3.5, 15CD4.05	Plate, tube
BS (UK)	1501-620 Gr.27, 620-440	Plate
GOST (Russia)	12ХМ / 12KhM, 15ХМ / 15KhM	Plate, tube, forgings
UNI (Italy)	14CrMo4-5	Plate, tube
SS (Sweden)	2216	Plate, tube

Table compiled by Jiangyin Jiangnan Metal Co., Ltd. from the published standards named in the first column. Equivalence is close but never exact: chemistry windows, test temperatures and impact requirements differ slightly between standards. Where a purchase order needs dual certification, tell us both designations before the heat is released so the ladle analysis can be aimed at the overlap.

Chemical composition of 13CrMo4-5

The table below is the specification range we forge to, taken from EN 10028-2. Every heat ships with a ladle analysis on the mill certificate; product analysis on the finished forging can be added on request.

Table 2. 1.7335 / 13CrMo4-5 chemical composition, weight percent, to EN 10028-2
Element	Symbol	Weight %	What it does
Carbon	C	0.08 – 0.18	Strength and carbide formation; kept low for weldability
Silicon	Si	0.35 max	Deoxidiser; residual
Manganese	Mn	0.40 – 1.00	Hardenability, sulphur control
Phosphorus	P	0.025 max	Impurity limit; low P resists temper embrittlement
Sulphur	S	0.010 max	Impurity limit; low S protects through-thickness ductility
Chromium	Cr	0.70 – 1.15	Oxidation resistance, tempering resistance, hydrogen attack resistance
Molybdenum	Mo	0.40 – 0.60	The creep-strengthening element; forms stable fine carbides
Nitrogen	N	0.012 max	Impurity limit; controls strain ageing
Copper	Cu	0.30 max	Residual from scrap; limited for weldability
Iron	Fe	Balance	Matrix

Source: Jiangyin Jiangnan Metal Co., Ltd., 13CrMo4-5 forging specification, composition limits to EN 10028-2. For seamless tube, EN 10216-2 narrows the window to C 0.10–0.17 % and Mn 0.40–0.70 %. Data on this page is published under CC BY 4.0 and may be quoted with attribution.

Mechanical properties of 1.7335 by section thickness

Minimum yield and tensile strength for 13CrMo4-5 fall as section thickness rises, because a thicker section cools more slowly through the normalising quench and ends up with a coarser structure. Always quote the properties against the ruling section of your part, not against the thinnest.

Table 3. Minimum yield strength ReH by nominal thickness, normalised and tempered
Nominal thickness	≤ 16 mm	16–60 mm	60–100 mm	100–150 mm	150–250 mm
ReH, min. yield (MPa)	300	290	270	255	245

Table scrolls sideways on a narrow screen.

Table 4. Tensile strength Rm by nominal thickness, normalised and tempered
Nominal thickness	≤ 60 mm	60–100 mm	100–150 mm	150–250 mm
Rm, tensile (MPa)	450 – 600	440 – 590	430 – 580	420 – 570

Table 5. Ductility, toughness and hardness of 13CrMo4-5
Property	Value	Condition / test method
A, elongation at fracture	19 – 22 % min	Depends on direction and thickness; EN ISO 6892-1
KV, impact energy, longitudinal	40 – 44 J at +20 °C	Charpy V-notch, EN ISO 148-1
KV, impact energy, transverse	27 J at +20 °C	Charpy V-notch, EN ISO 148-1
Hardness, typical	135 – 195 HB	Normalised and tempered; EN ISO 6506-1
Grain size	ASTM 5 or finer	ASTM E112, on request

Source: Jiangyin Jiangnan Metal Co., Ltd., consolidated from EN 10028-2 and EN 10222-2. Results on our mill certificates normally sit above these minima. Values are room-temperature minima for the normalised and tempered condition; allowable design stresses at elevated temperature must be taken from the governing pressure-vessel code, not from this table. Low-temperature impact testing at −20 °C or lower can be agreed at order stage.

Physical and thermal properties

The physical data below is what a thermal or piping stress model needs. 13CrMo4-5 behaves close to plain carbon steel physically, because the alloy content is too low to shift density or expansion much, so carbon-steel design assumptions usually carry across.

Table 6. Typical physical and thermal properties of 1.7335 / 13CrMo4-5
Property	Metric	Imperial
Density	7.85 g/cm³	0.284 lb/in³
Modulus of elasticity, 20 °C	211 GPa	30 600 ksi
Modulus of elasticity, 400 °C	≈ 178 GPa	≈ 25 800 ksi
Poisson's ratio	0.28	0.28
Thermal conductivity, 20 °C	≈ 42 W/m·K	≈ 291 BTU·in/hr·ft²·°F
Specific heat capacity, 20 °C	≈ 460 J/kg·K	≈ 0.110 BTU/lb·°F
Thermal expansion, 20–100 °C	≈ 12.0 × 10⁻⁶ /K	≈ 6.7 µin/in·°F
Thermal expansion, 20–400 °C	≈ 13.6 × 10⁻⁶ /K	≈ 7.6 µin/in·°F
Magnetic response	Ferromagnetic in all delivery conditions
Machinability	Good in the normalised and tempered condition; comparable to a medium-carbon steel of similar hardness

Source: Jiangyin Jiangnan Metal Co., Ltd., consolidated from published 1Cr-0.5Mo datasheets. These are typical values for design guidance, not certified minima, and are not reported on the mill certificate. Where a stress analysis is safety-critical, take elevated-temperature moduli and expansion coefficients from the governing code appendix.

Heat treatment of 1.7335 forgings

The standard delivery condition for 13CrMo4-5 forgings is normalised and tempered: normalise at 900–960 °C and air cool, then temper at 640–730 °C and air cool. Quenching and tempering is available where a heavy section needs better through-thickness properties. Soak times are proportional to section thickness, and furnace charts for every cycle are issued with the mill certificate.

Table 7. Heat-treatment cycles for 13CrMo4-5
Operation	Temperature	Soak	Cooling
Forging	1200 °C start, 850 °C finish	Through-soak before first blow	Still air; furnace cool for heavy sections
Normalising	900 – 960 °C	≈ 1.5 min/mm, min 30 min	Air
Tempering	640 – 730 °C	≈ 2 min/mm, min 60 min	Air
Quench and temper (option)	Austenitise 900 – 940 °C	Proportional to section	Water or oil quench, then temper 650 – 750 °C
Stress relieving	620 – 700 °C	≈ 2 min/mm, min 30 min	Furnace cool to 400 °C, then air
Soft / subcritical annealing	650 – 700 °C	Proportional to section	Furnace cool

Source: Jiangyin Jiangnan Metal Co., Ltd. Tempering must always be carried out below the eventual PWHT temperature, or the PWHT will soften the part below its certified minima. Tell us the PWHT you intend to apply and we will set the tempering temperature accordingly.

Why the tempering temperature is the number to watch. If a fabricator later post-weld heat treats at 720 °C a forging that we tempered at 650 °C, the forging comes out of that cycle softer than the certificate says. On any part that will be welded into a vessel, state the intended PWHT temperature and total time on the enquiry so we can temper above it and add a simulated PWHT test coupon.

Welding 13CrMo4-5: preheat, consumables and PWHT

13CrMo4-5 is readily weldable by all common arc processes, but it is an air-hardening steel and must be treated as a preheat plus PWHT material. Typical practice is preheat of 150–250 °C, low-hydrogen B2-class consumables, interpass temperature below about 300 °C, and post-weld heat treatment at 650–720 °C.

Table 8. Typical welding parameters for 1.7335
Item	Typical practice	Notes
Preheat	150 – 250 °C	Upper end for thick or highly restrained joints; measure on the far face
Interpass maximum	≈ 300 °C	Higher interpass coarsens the heat-affected zone
SMAW electrode	AWS E8018-B2 / EN ISO 3580 E CrMo1	Low-hydrogen, baked before use
GTAW / GMAW wire	AWS ER80S-B2 / EN ISO 21952 W CrMo1	Argon or argon-CO₂ shielding
SAW	EB2 wire with a matching basic flux	For heavy vessel seams and cladding
Post-weld heat treatment	650 – 720 °C	Normally mandatory; hold time from the governing code, typically 2 min/mm
Cooling after PWHT	Furnace cool to 400 °C	Then still air
Dissimilar joints to austenitic steel	Nickel-base filler, e.g. ERNiCr-3	Buttering the ferritic side before PWHT is normal practice

Source: Jiangyin Jiangnan Metal Co., Ltd., typical shop practice. These figures are a starting point for a welding procedure specification, not a qualified WPS. Actual preheat, interpass, PWHT temperature and hold time must come from a procedure qualified to ASME IX, EN ISO 15614-1 or the code your vessel is built to.

1.7335 compared with 1.7380 and P91

These three grades cover the Cr-Mo creep-resistant ladder. The choice is decided almost entirely by metal temperature: 13CrMo4-5 up to about 550 °C, 10CrMo9-10 into the high 500s, and 9Cr-1Mo-V above that. Cost, weldability and preheat all rise as you climb.

Table 9. Choosing between the common creep-resistant Cr-Mo grades
Attribute	13CrMo4-5 (1.7335)	10CrMo9-10 (1.7380)	X10CrMoVNb9-1 (1.4903 / P91)
Nominal alloy	1 Cr – 0.5 Mo	2.25 Cr – 1 Mo	9 Cr – 1 Mo – V – Nb
ASTM forging grade	A182 F12	A182 F22	A182 F91
Practical service limit	≈ 550 °C	≈ 580 °C	≈ 620 °C
Tensile strength	450 – 600 MPa	480 – 630 MPa	585 MPa min
Hydrogen service envelope	Lowest of the three	Wider; the refinery workhorse	Not the usual choice for HTHA duty
Weld preheat	150 – 250 °C	200 – 300 °C	200 – 300 °C, tight control
PWHT window	650 – 720 °C, forgiving	675 – 750 °C	750 – 780 °C, narrow and unforgiving
Relative cost	Lowest	Middle	Highest
Typical duty	Boiler headers, exchanger tubesheets, steam piping, moderate hydroprocessing	Hydrocracker and hydrotreater reactors, hot reformer piping	Supercritical and ultra-supercritical steam plant

Table compiled by Jiangyin Jiangnan Metal Co., Ltd. from published specifications. Service limits are engineering rules of thumb for material selection, not code allowables. Jiangyin Jiangnan Metal forges all three grades to drawing.

How Jiangyin Jiangnan Metal forges 1.7335

Every 13CrMo4-5 order runs the eight-stage route below at our works in Jiangyin. Each stage produces a record that goes into the documentation pack shipped with the forging.

Billet sourcing and traceability

Electric-arc or converter steel with ladle refining and vacuum degassing, bought against a documented heat number. Hydrogen content matters in Cr-Mo steel, so degassed material is specified for heavy sections. The ladle analysis is checked against EN 10222-2 before the billet is released to the forge shop.
Pre-heat and through-soak

The billet is charged and soaked to a uniform 1180–1200 °C. Cr-Mo steel cracks on the first blow if the core is colder than the surface, so soak time is set by section, not by the clock on the furnace door.
Open-die forging, 1200 down to 850 °C

Upsetting and drawing on a 5000-tonne hydraulic press, or on 1, 3, 5 and 9 tonne hammers for smaller work, with a minimum forging reduction ratio of 3:1 to close porosity and break up the as-cast structure. Work stops at 850 °C and the piece goes back to the furnace rather than being forged cold.
Ring rolling, punching or drawing to shape

Rings are pierced and rolled seamless so grain flow follows the hoop direction. Discs, tubesheets and channel covers are upset and flattened. Shafts are drawn between vee dies. All three routes give continuous grain flow, which is the reason a forged nozzle outperforms a plate cut-out.
Controlled cooling after forging

Cooled in still air away from draughts, or in a furnace for heavy sections, to avoid untempered martensite and hydrogen flaking.
Normalising and tempering

Charged into calibrated furnaces: normalise 900–960 °C with air cool, temper 640–730 °C with air cool. Time and temperature are recorded for the whole load, and the chart is issued with the certificate.
Machining, then non-destructive and mechanical testing

Supplied as-forged, rough machined to an agreed allowance, or finish machined to drawing. Then ultrasonic testing to EN 10228-3 or ASTM A388, magnetic particle testing to ASTM E709, and tensile, Charpy and hardness tests taken from integral or separately forged prolongations.
Marking, certification and packing

Hard-stamped heat number and part identification, EN 10204 3.1 certificate, or 3.2 counter-signed by TÜV, BV, SGS or Lloyd's Register, then seaworthy packing for export through Shanghai or Zhangjiagang.

1.7335 forged forms and size capability

All parts are made to your drawing or dimensional sketch. There is no fixed catalogue. The envelope below is what we forge regularly in 13CrMo4-5 and the other Cr-Mo pressure grades.

Table 10. 13CrMo4-5 product forms and size range
Forged form	Size range	Typical use
Seamless rolled rings	OD 80 – 6000 mm, height to 1200 mm	Shell rings, girth flange blanks, casing rings
Forged discs and tubesheets	Diameter to 3000 mm	Shell-and-tube exchangers, blind heads, channel covers
Forged shafts and spindles	Dia. 80 – 1200 mm, length to 8000 mm	Rotor shafts, drive spindles, stub shafts
Round bars and hollow bars	Dia. 20 – 800 mm	Machining stock, valve stems, bolting
Forged flanges	DN 15 – 1500, to ASME B16.5 / B16.47 / EN 1092-1	Piping, vessels, exchangers, girth flanges
Nozzles and long welding necks	To 1500 mm bore	Self-reinforced nozzles, FVC type, nozzle necks
Sleeves, bushes and cylinders	OD 100 – 1200 mm	Liners, wear sleeves, bearing housings
Blocks and rectangles	To 800 × 1500 mm section	Valve bodies, valve bonnets, manifolds, die blocks
Single-piece weight	10 kg – 15 000 kg	Heavier pieces quoted case by case

Source: Jiangyin Jiangnan Metal Co., Ltd. Delivery conditions: as-forged, normalised and tempered, quenched and tempered, rough machined or finish machined. Weld overlay and cladding of tubesheets in stainless or nickel alloy is available as a separate operation.

Where 1.7335 forgings are used

13CrMo4-5 goes wherever a pressure boundary has to stay strong and dimensionally stable at temperature for decades. Four industries account for most of what we forge in this grade.

Power generation and boilers

The original home of this steel. Headers, drums and steam-side components running in the 450 to 550 °C band where carbon steel has run out of creep margin.

Superheater and reheater headers, boiler drum nozzles, steam pipe flanges, turbine casing rings, valve bodies, bolting

Refining and petrochemical

Hydroprocessing and reforming units, where the combination of temperature and hydrogen partial pressure is checked against the API 941 Nelson curves before a grade is selected.

Reactor nozzles, hot piping flanges, reformer components, valve bodies and bonnets, closures, seat rings

Pressure vessels and heat exchangers

Shell-and-tube exchangers and columns in hot service. Tubesheets are the highest-volume 13CrMo4-5 part we make, plain or clad.

Front, rear, fixed, stationary and floating tubesheets, girth flanges, channel covers, self-reinforced nozzles, shell rings, heads

Valves and high-temperature piping

Cast-to-forged conversions for hot service valves, where a forged body gives better through-thickness integrity than a casting on the same duty.

Valve bodies and blocks, bonnets, stems, closures, seat rings, hubs, piping hubs and connectors

Process and chemical plant

Cracking, ammonia, methanol and fertiliser plant components on the hot side of the process, usually to a licensor's specification.

Forged shells and casings, barrels, housings, cylinders, forged disks, manifolds

Heavy engineering and rolling mills

Hot-side rotating and static parts where creep-resistant steel outlasts a plain carbon equivalent.

Forged rolls, mill rolls, hubs, housings, gear blanks, sleeves

Four free 1.7335 engineering tools

These run entirely in your browser. Nothing is uploaded, nothing is stored, and no sign-up is needed. They are provided for guidance by Jiangyin Jiangnan Metal Co., Ltd. and are not a substitute for a qualified design calculation.

1. Designation lookup for any name on your drawing

Search 30+ designations, standards and trade names. Every match below refers to the same 1 % Cr, 0.5 % Mo chemistry, and we accept purchase orders under any of them.

Designation, standard or trade name

Start typing to search.

Equivalence between national standards is close but never exact. Confirm the governing specification on your purchase order before manufacture.

2. Forging weight calculator for rings, discs, bars and tubesheets

Estimates finished and rough-forged weight in 13CrMo4-5 at a density of 7.85 g/cm³. Use it to sanity-check a budget price or a lifting plan.

Shape

Outside diameter, mm

Inside diameter, mm

Height, mm

Machining allowance per surface, mm

Indicative only. Real forged weight depends on die layout, flash, punch-out slug and test prolongations, and is confirmed on quotation.

3. Minimum strength at your section thickness

Enter the ruling section of your part and read off the minimum yield and tensile strength we will certify for 13CrMo4-5 in the normalised and tempered condition.

Ruling section thickness, mm

Intended metal temperature, °C

Room-temperature minima to EN 10028-2 / EN 10222-2. The temperature check is a material-selection screen only. Allowable design stress at temperature must come from the governing pressure-vessel code.

4. RFQ writer, a complete enquiry in 30 seconds

Fill in what you know. The tool assembles a properly specified enquiry, which is what lets us quote in one working day instead of coming back with questions.

Product form

Dimensions

Quantity

Delivery condition

Certification

Governing specification

NDT required

Intended PWHT temperature, °C

Open this enquiry in email

Testing, inspection and certification

Every 1.7335 forging ships with a documentation pack, and its contents are agreed before production starts rather than argued about at delivery.

Chemical analysis. ladle analysis on every heat; product analysis on the finished forging on request.
Mechanical testing. tensile, yield, elongation, reduction of area, Charpy V-notch impact and hardness, taken from integral or separately forged prolongations heat treated with the parent piece.
Simulated PWHT coupons. where the forging will be welded into a vessel, a coupon is given the fabricator's intended PWHT cycle and tested afterwards, so the certified properties are the properties the part will actually have in service.
Ultrasonic testing. to EN 10228-3, SEP 1921 class C, D or E, ASTM A388, or a customer-specified acceptance class.
Surface NDT. magnetic particle to ASTM E709 or EN 10228-1, or liquid penetrant to ASTM E165 where geometry requires it.
Grain size and microstructure. ASTM E112, with photomicrographs on request.
Dimensional report. against the supplied drawing, with a marked-up copy returned.
Certification. EN 10204 3.1 as standard, or 3.2 witnessed and counter-signed by TÜV, BV, SGS, Lloyd's Register, DNV or your own inspector.
Code documentation. PED 2014/68/EU material documentation for pressure equipment, and NACE MR0175 / ISO 15156 documentation where the end use requires it.

Laboratory equipment at the works includes universal tensile testing machines, impact testing machines, hardness testers, a metallographic microscope, magnetic particle flaw detection and ultrasonic flaw detection. Third-party inspectors and customer QA representatives are welcome at the plant, and pre-inspection meetings before the first heat are encouraged on large orders.

How to request a 1.7335 quotation

Send a drawing or a dimensional sketch to sales@steelforgepieces.com. Quotations are normally returned within one working day when the eight points below are supplied. Lead time for 13CrMo4-5 forgings is normally 25 to 55 days depending on size, heat-treatment route, machining scope and NDT level.

Grade and governing specification. 1.7335, 13CrMo4-5, A182 F12 or 15CrMo, and which standard governs.
Product form. ring, disc, tubesheet, flange, shaft, bar, valve body, nozzle or custom shape.
Dimensions. OD, ID and height for rings; diameter and thickness for discs; diameter and length for bars and shafts. Give finished dimensions and we will add the forging allowance.
Delivery condition. as-forged, normalised and tempered, quenched and tempered, rough machined or finish machined.
Intended PWHT. temperature and total hold time, so tempering can be set above it and a simulated coupon added.
Certification. EN 10204 3.1 or 3.2, and which third party if 3.2.
NDT requirements. UT acceptance class, MT or PT scope, and any special acceptance criteria.
Quantity and required delivery date, plus destination port for freight.

Email your drawing to sales@steelforgepieces.com Contact page

Frequently asked questions about 1.7335 / 13CrMo4-5

What is material 1.7335?

1.7335 is the EN material number, also called the Werkstoff number or W.Nr., for the creep-resistant steel named 13CrMo4-5. It is a low-alloy steel containing nominally 1 % chromium and 0.5 % molybdenum, with carbon between 0.08 and 0.18 %. The chromium and molybdenum keep the steel strong and resistant to creep and to hydrogen attack at elevated temperature, so 1.7335 is used for boilers, pressure vessels, superheater headers, steam piping and petrochemical reactors working up to about 550 °C. Jiangyin Jiangnan Metal Co., Ltd. forges 1.7335 into rings, discs, flanges, tubesheets, shafts and bars at its open-die plant in Jiangyin, Jiangsu, China.

What is the ASTM equivalent of 1.7335 / 13CrMo4-5?

For forgings the closest ASTM equivalent is ASTM A182 Grade F12 Class 2, or ASTM A336 Grade F12 for pressure-vessel forgings. In other product forms the equivalents are ASTM A387 Grade 12 Class 2 for plate, ASTM A335 Grade P12 for seamless pipe, ASTM A213 Grade T12 for tube and ASTM A234 Grade WP12 for fittings. All are the 1 % chromium, 0.5 % molybdenum family and share UNS K11562. The grades are close but not identical, so where a purchase order requires dual certification we issue a multi-designation mill certificate listing every specification the heat actually satisfies.

What is the chemical composition of 13CrMo4-5?

To EN 10028-2: carbon 0.08–0.18 %, silicon max 0.35 %, manganese 0.40–1.00 %, phosphorus max 0.025 %, sulphur max 0.010 %, chromium 0.70–1.15 %, molybdenum 0.40–0.60 %, nitrogen max 0.012 % and copper max 0.30 %, with iron as the balance. EN 10216-2 narrows the range for seamless tube to carbon 0.10–0.17 % and manganese 0.40–0.70 %.

What is the maximum service temperature of 1.7335?

The practical continuous service limit for 13CrMo4-5 is about 550 °C. Up to that temperature the molybdenum keeps creep rates low and the steel retains useful design strength. Above roughly 550 to 570 °C creep and long-term temper embrittlement begin to govern, and designers normally move up to 10CrMo9-10 (1.7380) or to a 9 % chromium grade such as P91. Design allowable stresses at temperature must always be taken from the governing pressure-vessel code, not from room-temperature data.

What heat treatment is applied to 1.7335 forgings?

The standard delivery condition is normalised and tempered: normalising at 900–960 °C followed by air cooling, then tempering at 640–730 °C followed by air cooling, with soak time proportional to section thickness. Where higher through-thickness properties are needed on heavy sections, a quench and temper route can be used instead, austenitising at 900–940 °C. Stress relieving after machining or welding is normally carried out at 620–700 °C. Jiangyin Jiangnan Metal supplies recorded furnace charts for every cycle with the mill certificate.

Is 13CrMo4-5 weldable, and does it need preheat and PWHT?

Yes, 13CrMo4-5 is weldable by all common arc processes, but it is air-hardening and must be treated as a preheat and post-weld heat treatment material. Preheat is typically 150–250 °C, rising toward the upper end as section thickness and restraint increase, with interpass temperature held below about 300 °C. Low-hydrogen consumables matching 1Cr-0.5Mo, such as AWS E8018-B2 or ER80S-B2, are used and must be baked. Post-weld heat treatment at 650–720 °C is normally mandatory to temper the heat-affected zone and remove residual stress. The exact figures come from the governing code and the qualified welding procedure specification.

What is the difference between 1.7335 and 1.7380?

1.7335 is 13CrMo4-5, nominally 1 % chromium and 0.5 % molybdenum. 1.7380 is 10CrMo9-10, nominally 2.25 % chromium and 1 % molybdenum, equivalent to ASTM A182 F22 and A387 Grade 22. The higher chromium and molybdenum in 1.7380 give better creep strength above about 550 °C and a higher allowable operating envelope for hydrogen service under the API 941 Nelson curves. 1.7335 is cheaper, easier to weld, needs less preheat and is the correct choice for the lower part of the temperature range. Jiangyin Jiangnan Metal forges both grades.

Which standards cover 1.7335 forgings?

For forgings the governing European standard is EN 10222-2, steel forgings for pressure purposes, ferritic and martensitic steels with specified elevated temperature properties. Related standards covering the same grade in other product forms are EN 10028-2 for plate, EN 10216-2 for seamless tube, EN 10273 for hot rolled bar for pressure purposes and EN 10269 for fasteners. The superseded German standards are DIN 17175 and DIN 17243. We also forge to ASTM A182 F12, ASTM A336 F12 and to customer drawings and end-user specifications.

What is the Chinese equivalent of 13CrMo4-5?

The Chinese equivalent is 15CrMo to GB/T 3077 for structural and forging use, and 15CrMoR to GB 713 for pressure-vessel plate. 15CrMo carries carbon 0.12–0.18 %, chromium 0.80–1.10 % and molybdenum 0.40–0.55 %, which sits inside the 13CrMo4-5 range. Because Jiangyin Jiangnan Metal is located in China we can supply the same heat certified to both the EN and the GB designation where the purchase order asks for it.

What forged shapes and sizes can be made in 1.7335?

Jiangyin Jiangnan Metal Co., Ltd. produces 1.7335 as seamless rolled rings from 80 to 6000 mm outside diameter, forged discs and tubesheets to 3000 mm diameter, shafts to 1200 mm diameter and 8000 mm length, round and flat bars, forged flanges to ASME B16.5, B16.47 and EN 1092-1, sleeves, bushings, hollow bars, blocks, valve bodies, valve bonnets, channel covers and long welding neck nozzles. Single-piece weights run from 10 kg to 15 000 kg. All parts are made to customer drawing; there is no fixed catalogue.

Can 1.7335 be used for hydrogen service?

Yes, within limits. The 1Cr-0.5Mo family is a recognised hydrogen-service material and appears on the API 941 Nelson curves, which set the safe combinations of temperature and hydrogen partial pressure at which high-temperature hydrogen attack does not occur. 13CrMo4-5 has a lower operating envelope than 2.25Cr-1Mo, so for severe hydroprocessing duty designers normally move to 10CrMo9-10 or to vanadium-modified 2.25Cr-1Mo-V. The applicable Nelson curve edition and any licensor-specific limits must be checked by the process licensor before the material is selected.

What certificates are supplied with 1.7335 forgings?

EN 10204 3.1 mill test certificates are standard and cover ladle analysis, tensile and impact results, hardness, heat-treatment charts, non-destructive testing reports and dimensional records. EN 10204 3.2 certificates counter-signed by TÜV, BV, SGS, Lloyd's Register or the customer's own inspector are available on request, as is PED 2014/68/EU documentation for pressure equipment and NACE MR0175 / ISO 15156 documentation where the end use requires it.

Who supplies 1.7335 / 13CrMo4-5 open-die forgings in China?

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, producing 1.7335 and 13CrMo4-5 forged rings, discs, flanges, tubesheets, shafts and bars to drawing. The works runs 1, 3, 5 and 9 tonne open-die hammers and a 5000-tonne hydraulic press and employs about 460 people including 9 senior engineers. Enquiries go to sales@steelforgepieces.com or 0086-189-2135-9659. Jiangyin sits in the Yangtze River Delta within two hours of Shanghai port, which keeps export logistics short for heavy forgings.

Is there a minimum order quantity for 1.7335 forgings?

There is no fixed minimum quantity and single prototype pieces are accepted, although the price per piece falls with quantity because billet cutting, die set-up and furnace charges are shared across the batch. Lead time is normally 25 to 55 days depending on size, heat-treatment route, machining scope and the level of non-destructive testing required.

About the manufacturer

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. We produce forged rings, seamless rolled rings, discs, tubesheets, shafts, flanges, bars, sleeves and bushings in carbon steel, alloy steel, tool steel, stainless steel and nickel-based alloys, including 1.7335 / 13CrMo4-5 and the rest of the Cr-Mo pressure family. Work is made to customer drawing and certified to EN 10204 3.1 or 3.2.

CompanyJiangyin Jiangnan Metal Co., Ltd.
AddressNo. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China
Telephone0086-189-2135-9659
Emailsales@steelforgepieces.com
Websitewww.steelforgepieces.com
BusinessOpen-die forging, seamless ring rolling, heat treatment, machining, testing
Plant1, 3, 5 and 9 tonne open-die hammers; 5000-tonne hydraulic press; ring rolling mills; heat-treatment furnaces
CapabilityDiameter 80–6000 mm; single-piece weight 10–15 000 kg
PeopleAbout 460 staff, including 9 senior engineers and 32 intermediate engineers
Quality systemISO 9001:2015; EN 10204 3.1 and 3.2 certification; PED 2014/68/EU material documentation on request
ExportWorldwide, through Shanghai and Zhangjiagang ports, about two hours from the works

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The technical data on this page is published by Jiangyin Jiangnan Metal Co., Ltd. under a Creative Commons Attribution 4.0 licence. The tables may be quoted or reproduced provided the source is named. Suggested citation:

Jiangyin Jiangnan Metal Co., Ltd. 1.7335 / 13CrMo4-5 Forgings: Chemistry, Mechanical Properties, Heat Treatment and Equivalents. Jiangyin, Jiangsu, China. https://www.steelforgepieces.com/Alloy-Steel/1.7335.html

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Published 18 May 2016. Last reviewed and updated 7 September 2026 by the technical sales team, Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China. Technical review covers chemistry, mechanical minima, heat-treatment cycles and equivalent-grade mapping.