---
title: "1.7375 (12CrMo9-10) Forgings and Rolled Rings, China Factory"
description: "1.7375 (12CrMo9-10) open-die forgings from Jiangyin Jiangnan Metal: rolled rings, discs, tubesheets, flanges and valve bodies. EN 10028-2 data."
canonical: "https://www.steelforgepieces.com/Alloy-Steel/1.7375.html"
grade_en_number: "1.7375"
grade_en_name: "12CrMo9-10"
uns: "K21590"
standard: "EN 10028-2"
supplier: "Jiangyin Jiangnan Metal Co., Ltd."
last_reviewed: "2026-09-07"
---

# 1.7375 Steel Forgings (12CrMo9-10)

1.7375 is the EN material number for 12CrMo9-10, a chromium-molybdenum creep-resistant steel specified in EN 10028-2 for pressure equipment working at elevated temperature. Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu, China that forges 1.7375 into seamless rolled rings, discs, tubesheets, valve bodies, flanges, shafts and shells, supplied normalised and tempered with EN 10204 material certificates.

Contact: sales@steelforgepieces.com | +86 189 2135 9659

## Grade at a glance

| Item | Value |
| --- | --- |
| EN material number | 1.7375 |
| EN designation | 12CrMo9-10 |
| Also written | 12CrMo910, 12CrMo9.10 |
| Alloy type | 2.25Cr-1Mo low-alloy steel |
| Data source standard | EN 10028-2 |
| Delivery condition | +NT or +QT |
| Yield strength ReH | 355 MPa min, t ≤ 250 mm |
| Tensile strength Rm | 540–690 MPa |
| Nearest ASTM grades | A182 F22 / A387 Gr.22 |
| UNS number | K21590 |

## What is 1.7375 steel?

1.7375 (12CrMo9-10) is a creep-resistant low-alloy steel containing 2.00–2.50% chromium and 0.90–1.10% molybdenum, specified in EN 10028-2 for pressure equipment operating at elevated temperature. It is supplied normalised and tempered, with a minimum yield strength of 355 MPa and a tensile strength of 540–690 MPa in thicknesses up to 250 mm.

The chromium forms a stable surface oxide that resists steam and flue-gas attack. The molybdenum precipitates as fine carbides that pin dislocations and slow creep deformation. Together they let the 2.25Cr-1Mo family serve in boiler headers, superheated steam piping, hydroprocessing reactors and high-temperature valves at temperatures where carbon steel would relax and creep.

Within EN 10028-2 there are three closely related grades in the same 2.25Cr-1Mo family: 10CrMo9-10 (1.7380), 11CrMo9-10 (1.7383) and 12CrMo9-10 (1.7375). They share almost the same chemistry. 1.7375 is the higher-strength member, specified at 355 MPa minimum yield against 250 to 310 MPa for 1.7380 depending on thickness. Designers pick it when they need more allowable stress from the same alloy system.

Jiangyin Jiangnan Metal supplies 1.7375 in forged form. Open-die forging refines the as-cast structure, closes centreline porosity and produces grain flow that follows the part contour. Pressure-equipment codes and refinery end users normally call for this on components that stay in creep service for decades.

## Chemical composition of 1.7375

1.7375 (12CrMo9-10) contains 0.10–0.15% C, 2.00–2.50% Cr and 0.90–1.10% Mo, with phosphorus limited to 0.015% and sulphur to 0.010%. The balance is iron.

Chemical composition of 1.7375 / 12CrMo9-10, weight %, per EN 10028-2. Ladle analysis is supplied on every certificate issued by Jiangyin Jiangnan Metal.

| Element | Symbol | Content (%) |
| --- | --- | --- |
| Carbon | C | 0.10 – 0.15 |
| Silicon | Si | max 0.30 |
| Manganese | Mn | 0.30 – 0.80 |
| Chromium | Cr | 2.00 – 2.50 |
| Molybdenum | Mo | 0.90 – 1.10 |
| Nickel | Ni | max 0.30 |
| Copper | Cu | max 0.25 |
| Aluminium | Al | 0.010 – 0.040 |
| Phosphorus | P | max 0.015 |
| Nitrogen | N | max 0.012 |
| Sulphur | S | max 0.010 |
| Iron | Fe | balance |

Aluminium acts as a deoxidiser and controls the free nitrogen that would otherwise cause strain ageing. Phosphorus and sulphur are held low because both promote temper embrittlement in Cr-Mo steel.

## Mechanical properties of 1.7375

In the normalised and tempered condition and in thicknesses up to 250 mm, 1.7375 has a minimum yield strength of 355 MPa, a tensile strength of 540–690 MPa, a minimum elongation of 18% and a transverse Charpy impact energy of 27 J at −20 °C.

Room-temperature mechanical properties per EN 10028-2, delivery condition +NT or +QT, nominal thickness up to 250 mm.

| Property | Symbol | Value |
| --- | --- | --- |
| Minimum yield strength | ReH | 355 MPa |
| Tensile strength | Rm | 540 – 690 MPa |
| Minimum elongation at fracture | A | 18 % |
| Impact energy, transverse, −20 °C | KV | 27 J |
| Impact energy, transverse, 0 °C | KV | 40 J |
| Impact energy, transverse, +20 °C | KV | 70 J |

Values are the specified minima for the base standard. Higher impact energy, lower test temperatures, through-thickness testing or simulated post-weld heat treatment can be agreed at enquiry stage and written into the test certificate.

## Indicative physical properties

Typical values for the 2.25Cr-1Mo family, for design guidance only.

| Property | Approximate value |
| --- | --- |
| Density | 7.85 g/cm³ |
| Modulus of elasticity at 20 °C | 210 GPa |
| Transformation temperature Ac1 | approx. 795 °C |
| Transformation temperature Ac3 | approx. 850 °C |
| Usual maximum service temperature | approx. 550 °C |

Take creep-rupture allowables, elevated-temperature yield and thermal expansion from the governing design code for your project, for example EN 13445, ASME VIII or the applicable national code.

## What is the ASTM equivalent of 1.7375?

The nearest ASTM and ASME grades to 1.7375 (12CrMo9-10) are ASTM A182 F22 and ASTM A387 Grade 22 for forgings and plate, both covered by UNS K21590. All belong to the 2.25Cr-1Mo family, but chemistry limits, classes and strength levels are not identical, so the exact grade and class must be stated on the purchase order.

| Standard or region | Designation | Typical product form |
| --- | --- | --- |
| EN 10028-2 (Europe) | 12CrMo9-10 (1.7375) | Flat products for pressure purposes |
| EN, same alloy family | 10CrMo9-10 (1.7380), 11CrMo9-10 (1.7383) | Plate, tube, forgings, bar |
| EN 10216-2 / EN 10273 | Same alloy family designations | Seamless tube, hot-rolled bar |
| ASTM / ASME (USA) | A182 F22, A336 F22, A387 Gr.22, A335 P22, A234 WP22 | Forgings, plate, pipe, fittings |
| UNS (USA) | K21590 | All forms |
| AFNOR (France) | 12CD9-10, 10CD9-10 | Plate, forgings |
| JIS (Japan) | SCMV4 (G 4109), STPA24 | Plate, tube |
| GB (China) | 12Cr2Mo1, 12Cr2Mo1R | Forgings, pressure-vessel plate |
| GOST (Russia) | 10Kh2M | Plate, forgings |
| ČSN (Czech) | 15 313 | Plate, forgings |
| Trade shorthand | 2.25Cr-1Mo, Chrome Moly, 12CrMo910 | All forms |

Cross-references indicate the closest known equivalents. Chemistry limits, delivery condition, heat-treatment requirements and impact-test acceptance differ between standards, and a grade that is equivalent for one product form may not be for another. Jiangyin Jiangnan Metal will confirm in writing which standard and class a given order will be manufactured and certified to before production starts.

## 1.7375 forgings we manufacture

Jiangyin Jiangnan Metal produces 1.7375 (12CrMo9-10) as seamless rolled rings, forged discs and tubesheets, flanges, valve bodies, shafts, sleeves, hollow bars and heat-exchanger components, machined to customer drawings and certified to EN 10204.

- **Seamless rolled rings.** Rolled to section on the ring mill, so the grain follows the circumference. Used for shell courses, girth rings, ring flanges, bearing races and retaining rings.
- **Discs, tubesheets and tube plates.** Forged discs, tubesheets and tube plates for shell-and-tube heat exchangers, including stationary, floating, front-head and rear-head plates, with drilled tube holes to drawing.
- **Clad and weld-overlay tubesheets.** 1.7375 base metal with stainless or nickel-alloy weld overlay on the process face, for hydroprocessing and sour service where the base metal needs corrosion protection.
- **Flanges and nozzles.** Girth flanges, channel covers, cover flanges, long welding neck flanges, nozzle necks and self-reinforced (FVC-type) nozzles, forged to size and machined ready for welding.
- **Valve components.** Valve bodies, valve blocks, bonnets, stems, closures and seat rings for high-temperature steam and hydrocarbon service, where 1.7375 replaces carbon steel above its creep limit.
- **Bars, hollow bars and sleeves.** Round bars, hollow bars, sleeves, bushes, bushings, barrels, cylinders, hubs and housings, forged and rough-turned or bored to a stated machining allowance.
- **Shafts and pressure shells.** Forged shafts, shells, casings, cases and blocks, including stepped shafts and hollow shells produced by upsetting, drawing and expanding on the open-die press.
- **Pipe and tubular forgings.** Forged pipes, piping spools, tubings and tubular sections in 1.7375 for sizes and wall thicknesses outside the seamless-tube mill range.
- **Custom open-die forgings.** One-off and small-batch parts forged to a customer drawing or a sketch with target dimensions.

## Available sizes and machining condition

| Product form | Size range | Single-piece weight |
| --- | --- | --- |
| Seamless rolled rings | OD 200 – 4000 mm | up to 10 t |
| Discs and tubesheets | diameter to 3000 mm | up to 15 t |
| Shafts and round bars | diameter 80 – 1200 mm | up to 15 t |
| Hollow bars and sleeves | OD to 1500 mm | up to 10 t |
| Flanges and valve bodies | to drawing | up to 10 t |

Supply condition options: as-forged, rough machined with a stated allowance, proof machined for ultrasonic testing, or finish machined to drawing. State the required allowance on the enquiry, because it changes both the forging weight and the heat-treatment response.

## How 1.7375 forgings are manufactured

Every 1.7375 forging at Jiangyin Jiangnan Metal follows the same route: vacuum-degassed steel, open-die forging or ring rolling, normalising and tempering, machining, non-destructive testing and mechanical testing, then certification to EN 10204.

1. **Steelmaking.** Ingot or bloom from electric-arc furnace steel refined by ladle furnace and vacuum degassing, so hydrogen and non-metallic inclusions are kept low. Electroslag remelted material is available where the specification calls for it.
2. **Open-die forging.** Upsetting and drawing on the hydraulic press to break down the cast structure. A minimum forging reduction ratio is agreed with the customer, commonly 3:1 or higher for pressure-retaining parts.
3. **Ring rolling.** For ring products, the pierced preform is rolled to final section on the ring mill, giving continuous circumferential grain flow and no weld seam.
4. **Heat treatment.** Normalising followed by tempering (+NT), or quenching and tempering (+QT), in furnaces with calibrated and recorded temperature control. Charts are retained and issued with the certificate on request.
5. **Machining.** Rough turning, boring, drilling and milling to the agreed allowance, or finish machining to drawing tolerances.
6. **Non-destructive testing.** Ultrasonic testing to EN 10228-3 or ASTM A388 with an agreed acceptance class, plus magnetic particle or dye penetrant inspection of machined surfaces and hardness survey.
7. **Testing and certification.** Ladle and product chemical analysis, tensile test, Charpy V-notch impact test at the specified temperature, and an EN 10204 3.1 certificate. Third-party inspection and 3.2 certification are arranged when required.

## Heat treatment, welding and temper embrittlement

1.7375 is normally normalised at about 900–960 °C and tempered at about 680–750 °C with air cooling. It is readily weldable using matching 2.25Cr-1Mo consumables with preheat of roughly 200–300 °C and post-weld heat treatment, which is mandatory in creep service.

Indicative parameters. Confirm against the governing specification and the customer's approved procedure before use.

| Operation | Temperature | Cooling |
| --- | --- | --- |
| Normalising | 900 – 960 °C | Still air |
| Tempering | 680 – 750 °C | Still air |
| Soft annealing | 650 – 700 °C | Furnace or still air |
| Preheat for welding | 200 – 300 °C | Maintain interpass |
| Post-weld heat treatment | 680 – 730 °C | Controlled furnace cooling |

### Welding

Use matching low-alloy consumables in the 2.25Cr-1Mo class, keep hydrogen low, hold preheat and interpass temperature throughout, and do not allow the joint to cool to ambient before post-weld heat treatment. Because 1.7375 works in creep service, the design code treats PWHT as a mandatory step. Declare the PWHT cycle the forging will later see at enquiry stage, so that mechanical testing can be carried out on simulated-PWHT samples.

### Temper embrittlement control

2.25Cr-1Mo steel held for long periods in the 350–575 °C range can suffer temper embrittlement, which raises the ductile-to-brittle transition temperature. The consequence appears during start-up and shutdown, when the metal passes back through the lower temperature range. Purchasers of hydroprocessing equipment therefore often impose residual-element limits in addition to the base standard, typically a Watanabe J-factor of 100 maximum on base metal and an X-bar of 15 ppm maximum on weld metal, sometimes with a step-cooling embrittlement test. For hydrogen service, the operating temperature and hydrogen partial pressure also have to sit inside the API 941 Nelson curve for 2.25Cr-1Mo.

Jiangyin Jiangnan Metal can source heats to tightened phosphorus, tin, antimony and arsenic limits when the enquiry states them. These are melt-shop requirements and have to be agreed before the heat is ordered.

## Where 1.7375 is used

1.7375 (12CrMo9-10) is used for pressure-retaining components in refineries, petrochemical plants and power stations that operate above the creep limit of carbon steel, typically between about 400 and 550 °C.

- **Refinery hydroprocessing.** Hydrotreater and hydrocracker reactor components, nozzles, closures and internals exposed to high-temperature hydrogen.
- **Shell-and-tube heat exchangers.** Tubesheets, channel flanges, girth flanges and channel covers for crude preheat trains, reformers and desulphurisers.
- **Boilers and steam plant.** Headers, drums, superheated steam piping components, steam-cooler and coil parts.
- **High-temperature valves.** Bodies, bonnets, stems and closures for main steam and hot hydrocarbon lines.
- **Pressure vessels.** Shells, heads, nozzles and forged rings for equipment designed to ASME VIII Div.1 and Div.2 or EN 13445.
- **Ammonia, hydrogen and coal-to-chemicals plant.** Reformer and converter components in continuous elevated-temperature duty.

## How to order 1.7375 forgings

To quote a 1.7375 forging accurately, Jiangyin Jiangnan Metal needs the grade and class, the governing standard, the drawing or dimensions, the delivery condition, the testing requirements and the certificate type. Enquiries go to sales@steelforgepieces.com.

1. **Grade and class.** 1.7375 / 12CrMo9-10, or the ASTM equivalent with its class, for example A182 F22 Class 3.
2. **Governing standard and edition.** EN 10028-2, EN 10222-2, ASTM A182 or a customer specification, with the year of issue.
3. **Product form and dimensions.** A drawing if you have one, otherwise OD, ID, height or thickness, and the machining allowance you want left on.
4. **Delivery condition.** +NT or +QT, and whether mechanical testing is to be on simulated post-weld heat-treated samples.
5. **Quantity and required delivery date.** Including whether this is a one-off, a prototype or a repeat order.
6. **Testing.** Tensile, Charpy test temperature and minimum energy, hardness, ultrasonic acceptance class and any through-thickness requirement.
7. **Certification.** EN 10204 2.2, 3.1 or 3.2, and the name of the third-party inspection body if 3.2 applies.
8. **Special requirements.** Temper-embrittlement limits, step cooling, NACE MR0175 / ISO 15156, PED 2014/68/EU material appraisal, AD 2000-W0, or marking and traceability rules.

## Frequently asked questions about 1.7375

### What is 1.7375 steel?

1.7375 is the EN material number for 12CrMo9-10, a creep-resistant low-alloy steel containing 2.00–2.50% chromium and 0.90–1.10% molybdenum. It is specified in EN 10028-2 for pressure equipment operating at elevated temperature and is normally supplied normalised and tempered.

### What is the EN name for material 1.7375?

The EN chemical designation for material number 1.7375 is 12CrMo9-10. It is also written 12CrMo910 or 12CrMo9.10, and referred to in the trade as 2.25Cr-1Mo or chrome-moly steel.

### What is the ASTM equivalent of 1.7375?

The closest ASTM grades are A182 F22 for forgings and A387 Grade 22 for plate, both carrying UNS number K21590. A335 P22 and A234 WP22 cover the same alloy for pipe and fittings. These are indicative equivalents: chemistry limits and strength classes differ, so the exact grade and class should be confirmed on the purchase order.

### What is the difference between 1.7375 and 1.7380?

Both are 2.25Cr-1Mo steels in EN 10028-2 with almost identical chemistry. 1.7375 (12CrMo9-10) is the higher-strength grade, specified at a minimum yield strength of 355 MPa and a tensile strength of 540–690 MPa. 1.7380 (10CrMo9-10) is specified at a lower strength level that falls with increasing thickness, from about 310 MPa down to 250 MPa minimum yield.

### What is the maximum service temperature of 1.7375?

1.7375 is generally used for continuous service up to about 550 °C. The limit for a given component follows from the design code and from the creep-rupture allowable stress at the design temperature and design lifetime.

### Is 1.7375 weldable?

Yes. 1.7375 is welded routinely with matching 2.25Cr-1Mo consumables, using preheat of roughly 200–300 °C, controlled interpass temperature, low-hydrogen practice and post-weld heat treatment at about 680–730 °C. Post-weld heat treatment is mandatory in creep service.

### What delivery condition are 1.7375 forgings supplied in?

Jiangyin Jiangnan Metal supplies 1.7375 forgings normalised and tempered (+NT), or quenched and tempered (+QT) where the specification calls for it. Mechanical testing on simulated post-weld heat-treated samples is available when the fabricator's PWHT cycle is declared at enquiry stage.

### Which forged products can be made in 1.7375?

Jiangyin Jiangnan Metal forges 1.7375 into seamless rolled rings, discs, tubesheets and tube plates, clad and weld-overlay tubesheets, girth flanges, channel covers, long welding neck flanges, nozzle necks, self-reinforced nozzles, valve bodies, bonnets, stems and closures, shafts, sleeves, bushes, hollow bars, cylinders, hubs, housings, shells and casings.

### Who supplies 1.7375 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, that manufactures 1.7375 (12CrMo9-10) forgings for export. Enquiries: sales@steelforgepieces.com or +86 189 2135 9659.

### What certificates are supplied with 1.7375 forgings?

An EN 10204 3.1 material certificate is issued as standard, covering chemical analysis, heat treatment condition, mechanical test results and traceable heat and part numbers. EN 10204 3.2 certification with third-party inspection by bodies such as TUV, SGS, BV or Lloyd's is arranged on request.

### Can 1.7375 forgings be supplied to tightened temper-embrittlement limits?

Yes, when the requirement is stated at enquiry stage. Limits such as a J-factor of 100 maximum and an X-bar of 15 ppm maximum are melt-shop requirements, so the heat has to be selected or ordered against them before forging begins. Step-cooling embrittlement testing can also be arranged.

### What is the lead time for 1.7375 forgings?

Lead time depends on whether suitable material is already in stock, the forging weight, the machining scope and the inspection requirements. Send the drawing and specification to sales@steelforgepieces.com and Jiangyin Jiangnan Metal will confirm a delivery date with the quotation.

## About the supplier

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China, on the south bank of the Yangtze between Shanghai and Nanjing. The works forges carbon steel, alloy steel, tool steel, stainless steel and nickel alloys into rings, discs, shafts, flanges, valve components and pressure-vessel parts, and exports to fabricators, valve makers and EPC contractors worldwide.

For 1.7375 (12CrMo9-10) the works supplies forgings from single prototype pieces to repeat production batches, machined to drawing and certified to EN 10204.

| | |
| --- | --- |
| Company | Jiangyin Jiangnan Metal Co., Ltd. |
| Address | No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China |
| Telephone | +86 189 2135 9659 |
| Email | sales@steelforgepieces.com |
| Website | https://www.steelforgepieces.com/ |

**Citing this page.** Data on this page is compiled by Jiangyin Jiangnan Metal Co., Ltd. from EN 10028-2 and from its own manufacturing practice. Reuse is permitted with attribution:

> Jiangyin Jiangnan Metal Co., Ltd., "1.7375 (12CrMo9-10) Steel Forgings", steelforgepieces.com, last reviewed 7 September 2026. https://www.steelforgepieces.com/Alloy-Steel/1.7375.html

Last reviewed 7 September 2026. Property values are taken from EN 10028-2. Where a value is marked indicative, it is typical practice for the 2.25Cr-1Mo family and is not a guarantee; confirm against the governing specification for your project.

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