# X155CrVMo12-1 (1.2379 / AISI D2) Forged Cold Work Tool Steel

Also listed as X153CrMoV12, X155CrVMo121, X155CrVMo12.1, JIS SKD11, GB Cr12Mo1V1, BS BD2 and AFNOR Z160CDV12. Supplied as open-die forged bars, blocks, hollow bars and seamless rolled rings.

**X155CrVMo12-1 is a high-carbon, high-chromium ledeburitic cold work tool steel, material number 1.2379, equivalent to AISI D2 and JIS SKD11.** It contains roughly 1.55 % carbon, 12 % chromium, 0.8 % molybdenum and 0.8 % vanadium, hardens to 63-65 HRC and is normally used at 60-62 HRC. Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory in Jiangyin, Jiangsu, China, supplies it as forged bars, blocks, hollow bars and rolled rings.

- Source page: https://www.steelforgepieces.com/Alloy-Steel/X155CrVMo12-1.html
- Publisher: Jiangyin Jiangnan Metal Co., Ltd.
- Last updated: 19 September 2026

## At a glance

| Item | Value |
|---|---|
| Steel group | Cold work tool steel, ledeburitic 12 % chromium type |
| Material number | 1.2379 |
| EN ISO 4957 name | X153CrMoV12 |
| DIN 17350 name | X155CrVMo12-1 |
| Closest US grade | AISI / ASTM D2 (UNS T30402) |
| Delivery condition | Soft annealed, max. 255 HB (EN ISO 4957); typically 235 HB or less as supplied |
| Tensile strength, annealed | approx. 850 N/mm2 (approx. 123 ksi) |
| Hardening temperature | 1020 degC, or 1060-1080 degC for maximum secondary hardening |
| Hardness as quenched | 63-65 HRC |
| Working hardness | 60-62 HRC after tempering |
| Main uses | Blanking and forming dies, shear blades, thread rolling dies, wear plates, mould plates and inserts |
| Supplied by | Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China. Open-die forged to order. |

## What is X155CrVMo12-1?

X155CrVMo12-1 is a through-hardening cold work tool steel defined by material number 1.2379. The high carbon content combines with 12 % chromium to form a dense network of hard chromium carbides, which is what gives the steel its abrasion resistance. Molybdenum and vanadium refine those carbides and add secondary hardening during tempering.

In current European practice the same steel is designated X153CrMoV12 under EN ISO 4957. X155CrVMo12-1 is the older DIN 17350 name that remains in wide commercial use. A mill certificate may carry either designation, and both mean 1.2379.

The grade is chosen when a tool must hold a cutting or forming edge against abrasive wear with very little dimensional change during heat treatment. It is not a shock-resisting steel: for high-impact work, a tougher grade such as 1.2363 (A2) or 1.2767 is usually the better choice.

### Characteristics

- Extremely high wear and abrasion resistance from the chromium carbide structure
- Excellent dimensional stability and low distortion in hardening
- Good through-hardenability in heavy sections
- Pronounced secondary hardening, so hot hardness is retained to about 500 degC
- Good compressive strength and edge retention
- Moderate machinability in the annealed condition; moderate toughness when hardened
- Not corrosion resistant despite the chromium content

## Chemical composition

Weight %, per EN ISO 4957 for X153CrMoV12 / 1.2379.

| Element | Min. % | Max. % | Typical analysis % |
|---|---|---|---|
| Carbon (C) | 1.45 | 1.60 | 1.53 |
| Silicon (Si) | 0.10 | 0.60 | 0.30 |
| Manganese (Mn) | 0.20 | 0.60 | 0.35 |
| Chromium (Cr) | 11.00 | 13.00 | 12.00 |
| Molybdenum (Mo) | 0.70 | 1.00 | 0.80 |
| Vanadium (V) | 0.70 | 1.00 | 0.80 |
| Phosphorus (P) | - | 0.030 | 0.025 max. |
| Sulphur (S) | - | 0.030 | 0.025 max. |
| Iron (Fe) | Balance | Balance | Balance |

The typical analysis column reflects the ladle chemistry Jiangyin Jiangnan Metal normally works to. Every forging is supplied with an EN 10204 3.1 mill test certificate stating the actual heat analysis.

## International equivalent grades

| Standard / country | Designation |
|---|---|
| Werkstoff no. (Germany) | 1.2379 |
| EN ISO 4957 (Europe) | X153CrMoV12 |
| DIN 17350 (Germany) | X155CrVMo12-1 |
| ASTM A681 / AISI (USA) | D2 (UNS T30402) |
| JIS G4404 (Japan) | SKD11 |
| GB/T 1299 (China) | Cr12Mo1V1 |
| BS 4659 (UK) | BD2 |
| AFNOR (France) | Z160CDV12 |
| UNI (Italy) | X155CrVMo121 / X160CrMoV12 |
| UNE (Spain) | X160CrMoV12 |
| SS (Sweden) | 2310 |
| GOST (Russia, near equivalent) | Kh12MF |

These grades are commercially interchangeable but the permitted element ranges are not identical between standards. GOST Kh12MF in particular carries less molybdenum and vanadium than 1.2379. State the governing standard on the purchase order when the application is critical.

## Physical and mechanical properties

| Property | Value (metric) | Value (imperial) |
|---|---|---|
| Density | 7.70 g/cm3 | 0.278 lb/in3 |
| Modulus of elasticity, 20 degC | 210 GPa | 30.5 x 10^6 psi |
| Thermal conductivity, 20 degC | approx. 20 W/(m K) | approx. 11.6 BTU/(h ft degF) |
| Thermal conductivity, 100 degC | 21 W/(m K) | 12.1 BTU/(h ft degF) |
| Specific heat capacity, 20 degC | approx. 460 J/(kg K) | approx. 0.11 BTU/(lb degF) |
| Thermal expansion, 20-100 degC | 10.5 x 10^-6 /K | 5.8 x 10^-6 /degF |
| Thermal expansion, 20-200 degC | 11.5 x 10^-6 /K | 6.4 x 10^-6 /degF |
| Thermal expansion, 20-400 degC | 12.2 x 10^-6 /K | 6.8 x 10^-6 /degF |
| Electrical resistivity, 20 degC | approx. 0.65 ohm mm2/m | approx. 65 micro-ohm cm |
| Tensile strength, soft annealed | approx. 850 N/mm2 | approx. 123 ksi |
| Hardness, soft annealed | max. 255 HB | max. 25 HRC |
| Hardness, as quenched | 63-65 HRC | 63-65 HRC |
| Hardness, tempered (working) | 60-62 HRC | 60-62 HRC |

## Heat treatment

| Operation | Temperature | Procedure and result |
|---|---|---|
| Forging | 1050 down to 900 degC | Heat slowly and uniformly; finish forging above 900 degC, then cool slowly in the furnace to avoid cracking. Soft anneal immediately after forging. |
| Soft annealing | 800-850 degC | Hold 2 to 5 hours, then cool under control at 10 to 20 degC per hour down to about 600 degC, then cool in air. Result: max. 235 HB. |
| Stress relieving | 600-650 degC | After rough machining. Hold about 2 hours, then cool slowly in the furnace to reduce distortion in hardening. |
| Preheating | 600-650 degC, then 850 degC | Two stages, equalised at each step. This grade must not be heated rapidly to austenitising temperature. |
| Hardening | 1020 degC or 1060-1080 degC | 1020 degC gives maximum toughness and minimum retained austenite; 1060-1080 degC gives maximum secondary hardening and hot hardness. Quench in oil, air, vacuum gas or a hot bath at 500-550 degC. Result: 63-65 HRC. |
| Tempering | 180-250 degC or 500-520 degC | Heat slowly to tempering temperature immediately after hardening to avoid cracking. Temper at least twice, and preferably three times at the secondary hardening peak, minimum 2 hours per cycle with cooling to room temperature in between. Rapid cooling after tempering improves dimensional stability. Result: 60-62 HRC. |
| Nitriding | 480-520 degC | Very well suited, because the hardness of the base material does not fall below 60 HRC at these temperatures. Surface hardness approx. 1000-1100 HV. |
| PVD coating | below the tempering temperature | A good base material for coating. Keep the coating temperature under the temperature used for the final temper so the core hardness is not lost. |

### Surface treatment and machining notes

- Polishing: gives the best result in the hardened condition.
- EDM, etching and hard chrome plating: all possible; temper again after EDM to remove the white layer.
- Machining: carried out in the soft-annealed condition. Carbide tooling is recommended because of the hard carbide network.
- Grinding: use soft, open-structure wheels and plenty of coolant to avoid grinding cracks.

## Applications

X155CrVMo12-1 is specified wherever abrasive wear, not impact, is the limiting factor.

| Area | Typical tools |
|---|---|
| Cutting and blanking | Blanking dies, punching dies, trim dies, plate cutting dies, slitting cutters, lamination dies, shear blades, rotary cutting blades, fine blanking tools |
| Forming | Forming dies, deep drawing tools, bending and flanging tools, coining dies, drawing dies, straightening rolls, tube section forming rolls |
| Thread and cold rolling | Thread rolling dies and jaws, knurling tools, die chasers, cold mill rolls, screw rolling rolls, seaming rolls |
| Cold extrusion | Cold extrusion dies, cold-heading tools, burnishing tools |
| Plastics processing | Mould plates and inserts with high wear resistance, dies for injection of thermosets, injection screw tip components |
| Wear parts | Wear plates, sliding guides, guide rails, jaw holders, gauges, sandblast nozzles, tyre shredder and scrap chopper knives |
| Knives | Food-processing knives, nail-making knives, woodworking and pelletising knives |

## Forged product forms and size range

Jiangyin Jiangnan Metal manufactures X155CrVMo12-1 by open-die forging and ring rolling, not by casting or by re-selling mill bar. Each item is forged to the customer's drawing or to a standard section.

| Product form | Size range | Notes |
|---|---|---|
| Round bars, rods, shafts | OD 80-1200 mm, length up to 6000 mm | Forged, soft annealed, black / rough turned / finish machined |
| Square and rectangular flat bars | Thickness 40-800 mm, width up to 1500 mm | Forged and milled on request |
| Blocks, discs, plates | Thickness 50-1000 mm, OD up to 2500 mm | Die plates and mould blocks |
| Hollow bars, sleeves, bushes | OD 200-2000 mm, ID from 100 mm | Bored and trepanned |
| Seamless rolled rings | OD 300-3000 mm, height up to 800 mm | Ring rolled, proof machined |
| Rolls and rollers | Barrel OD up to 1000 mm | With integral or shrunk-on journals |

### Process route and quality control

1. Electric arc furnace or induction melting with ladle refining; ESR remelting available on request for critical tooling.
2. Open-die forging or ring rolling with a controlled forging ratio to break down the as-cast carbide network.
3. Soft annealing to a machinable, uniform structure.
4. Ultrasonic testing to EN 10228-3 or ASTM A388, plus dimensional and hardness inspection.
5. Release with an EN 10204 3.1 mill test certificate covering chemistry, hardness, UT and dimensions.

## Frequently asked questions

**What is X155CrVMo12-1 steel?**
X155CrVMo12-1 is a high-carbon, high-chromium ledeburitic cold work tool steel with about 1.55 % carbon and 12 % chromium. Its material number is 1.2379. It is through-hardening, extremely wear resistant and dimensionally stable, and is used for blanking dies, forming dies, shear blades, thread rolling dies and plastic mould inserts.

**Is X155CrVMo12-1 the same as AISI D2?**
Yes. X155CrVMo12-1 (1.2379) is the European equivalent of AISI D2, and of JIS SKD11 and GB Cr12Mo1V1. The grades share the same 12 % chromium ledeburitic composition and are interchangeable in most cold work tooling applications, although the permitted element ranges differ slightly between standards, so the exact specification should be stated on the order.

**What is the difference between X155CrVMo12-1 and X153CrMoV12?**
They are the same steel. X155CrVMo12-1 is the older DIN 17350 designation and X153CrMoV12 is the current designation used in EN ISO 4957. Both refer to material number 1.2379, and mill certificates may use either name.

**What hardness can X155CrVMo12-1 reach?**
X155CrVMo12-1 reaches 63-65 HRC as quenched from 1020-1080 degC. After tempering, the usual working hardness is 60-62 HRC. It is supplied soft annealed at a maximum of 255 HB so that it can be machined before hardening.

**How is X155CrVMo12-1 heat treated?**
Soft anneal at 800-850 degC for 2 to 5 hours with controlled cooling of 10 to 20 degC per hour to about 600 degC, then cool in air. Harden from 1020 degC for maximum toughness, or 1060-1080 degC for maximum secondary hardening, quenching in oil, air, vacuum gas or a hot bath. Temper at least twice, and preferably three times, for a minimum of two hours per cycle.

**Can X155CrVMo12-1 be nitrided or coated?**
Yes. The grade is well suited to nitriding because the hardness of the base material stays above 60 HRC after the nitriding cycle. It is also a good base material for PVD coating, provided the coating temperature stays below the tempering temperature used. EDM, etching and hard chrome plating are all possible.

**Is X155CrVMo12-1 stainless or corrosion resistant?**
No. Although it contains about 12 % chromium, most of that chromium is bound in carbides rather than dissolved in the matrix, so the steel is not stainless. Tools should be oiled or otherwise protected in storage, and the grade should not be selected for corrosive service.

**In which forged shapes can X155CrVMo12-1 be supplied?**
Jiangyin Jiangnan Metal supplies X155CrVMo12-1 as open-die forged round bars, square and rectangular flat bars, blocks, discs and plates, hollow bars, sleeves and bushes, shafts and rolls, and seamless rolled rings. Material is normally delivered soft annealed, rough machined or finish machined to drawing.

**Who supplies forged X155CrVMo12-1 in China?**
Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, manufactures X155CrVMo12-1 forgings to order. Enquiries can be sent to sales@steelforgepieces.com or by phone to +86-189-2135-9659.

## Related cold work tool steel grades

- [1.2080 / X210Cr12](https://www.steelforgepieces.com/Tool-Steel/1.2080.html): higher carbon, no molybdenum; greater wear resistance, lower toughness.
- [1.2363 / X100CrMoV5 (AISI A2)](https://www.steelforgepieces.com/Tool-Steel/1.2363.html): air hardening, tougher, for tools that see impact.
- [1.2510 / 100MnCrW4 (O1)](https://www.steelforgepieces.com/Tool-Steel/1.2510.html): oil hardening, for smaller tools and gauges.
- [1.2344 / X40CrMoV5-1 (H13)](https://www.steelforgepieces.com/Tool-Steel/1.2344.html): hot work grade, for die casting and hot forming.

## Reference standards

- EN ISO 4957: Tool steels (designates 1.2379 as X153CrMoV12)
- DIN 17350: Tool steels, technical delivery conditions (designation X155CrVMo12-1)
- ASTM A681: Standard specification for tool steels, alloy (grade D2)
- JIS G4404: Alloy tool steels (grade SKD11)
- GB/T 1299: Tool and die steels (grade Cr12Mo1V1)
- EN 10204: Types of inspection documents for metallic products
- EN 10228-3 and ASTM A388: Ultrasonic testing of steel forgings

## Supplier

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. It forges round bars, flat bars, blocks, discs, hollow bars, sleeves, shafts, rolls and seamless rolled rings in carbon steel, alloy steel, tool steel, stainless steel and nickel alloys.

- Address: No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Telephone and WhatsApp: +86-189-2135-9659
- Email: sales@steelforgepieces.com
- Website: https://www.steelforgepieces.com/

Reference as: Jiangyin Jiangnan Metal Co., Ltd., "X155CrVMo12-1 (1.2379 / AISI D2) Forged Cold Work Tool Steel", steelforgepieces.com, 19 September 2026.

The values given above are typical or standard values for guidance. They are not guaranteed properties for any particular delivery. Confirm requirements against the governing specification and the mill test certificate supplied with your order.