Known globally for its exceptional wear resistance, edge retention and dimensional stability, DIN 1.2379 has earned its reputation as a dependable workhorse for cold work applications. At Toolman Special Steels, we’ve worked closely with this grade for decades, supplying it to toolmakers and manufacturers across India, Europe, USA, Japan, Turkey and China.

What is DIN 1.2379?

DIN 1.2379 (equivalent to AISI D2) is a high-carbon, high-chromium cold work tool steel. Its chemistry is engineered to deliver extreme hardness and abrasion resistance, which makes it ideal for tools that operate under intense mechanical stress without exposure to high heat.

What sets DIN 1.2379 apart is its ability to hold a sharp cutting edge for long production runs, even in abrasive environments. That’s why it’s widely used in high-volume manufacturing where downtime is costly.

DIN 1.2379 Typical Composition (% by weight):

Element	Min (%)	Max (%)
C	1.4	1.6
Si	0.10	0.6
Mn	0.1	0.6
P	-	0.030
S	-	0.030
Cr	11	13
Mo	0.7	1.2
V	0.5	1.1

The high chromium content promotes carbide formation, which directly contributes to wear resistance and long tool life.

DIN 1.2379 Mechanical Properties After Heat Treatment 

DIN 1.2379 is not designed for impact-heavy applications – but where wear resistance and edge retention matter most, it excels.

Property	Value
Hardness (HBW)	255 max (Annealed)
Quenching and Tempering Hardness (HRC)	59 min (Annealed)
Poisson’s Ratio	0.27-0.30
Impact Toughness	77 J/cm2
Tensile Strength	1860-2060 MPa
Yield Strength	1600-1800 MPa

DIN 1.2379 is not designed for impact-heavy applications but where wear resistance and edge retention matter most, it excels.

Physical & Mechanical Properties

Property	Condition / Temperature	Value	Unit
Density	Room Temperature	7.7	g/cm³
Modulus of Elasticity	20 °C	210	GPa

Thermal Properties

Temperature (°C)	Thermal Expansion Coefficient (10⁻⁶/°C)	Thermal Conductivity (W/m·K)
20	—	20
400	13.8	—
500	14.1	—

Why DIN 1.2379 Works So Well in Cold Work Applications

Cold work tooling often faces repeated mechanical loads, sharp contact stresses and abrasive wear – without the benefit of elevated operating temperatures that soften material behavior.

DIN 1.2379 thrives here because:

• High carbide volume = superior abrasion resistance
• High hardness = excellent edge life
• Stable microstructure = consistent performance across batches

Common Applications:

• Blanking & punching dies
• Shear blades, slitter knives & tyre shredders
• Cold forming & drawing dies
• Rollers and knives for industrial cutting applications
• Gauges & measuring tools
• High-performance cutting tools
• Stamping and pressing dies
• Woodworking cutting tools
• Drawing and deep-drawing dies
• Shear blades and slitter knives
• Rolls and wear-resistant components
• Gauges and measuring tools
• Plastic mould components
• Tooling for ceramics and pharmaceutical industries

It’s especially popular in automotive stamping, sheet metal processing and industrial knife manufacturing.

Some of the related applications are also discussed in detail in our other technical articles:

• From Forge to Finish – The Steel Behind Premium Knives
• 440B Stainless Steel for Industrial Precision Applications

 Need DIN 1.2379 for dies, blades, or stamping tools?
Request a datasheet or quote from Toolman Special Steels.

Heat Treatment & Processing

DIN 1.2379 is typically supplied in the annealed condition (~230 HB) for ease of machining.

Process	Temperature	Duration	Cooling Method
Soft Annealing	820 - 850	2-5 hours	Furnace
Stress-relief Annealing	600 - 650	min 4 hrs	Furnace
Hardening	1000 - 1050	Group III	oil, air, WB 500°C
Tempering	480 - 580 see tempering curve	min 2 hrs Depending on cross section	still air

Tempering °C	HRC
100	63
200	61
300	58
400	58
500	59
525	58
550	56
600	51

Proper heat treatment is crucial. At Toolman, every batch is processed with controlled cycles to ensure hardness consistency and minimal distortion.

DIN 1.2379 vs Other Tool Steel Grades 

Choosing the right tool steel depends on whether the application prioritizes wear resistance, toughness, heat resistance, or dimensional stability. 

Grade	Best Feature	Typical Use
DIN 1.2379 / AISI D2	Wear resistance and edge retention	Dies, blades, stamping tools
DIN 1.2080 / D3	Higher abrasion resistance	Heavy wear tooling
A2 Tool Steel	Better toughness than D2	Impact-sensitive cold work tools
H13 / DIN 1.2344	Heat resistance	Hot work tooling, die casting, extrusion
DIN 1.2367	Toughness and thermal performance	Heavy-duty hot work tools

Manufacturing Range

Products	Diameter (mm)
Hot Rolled bar	8 - 65
Forged and Turned bars	65.2 - 500
Forged Square Bars	50 - 500

Flats

Thickness	Width
6.00 mm - 410.00 mm	20.00 mm - 700.00 mm

Our reputation as one of the leading DIN 1.2379 cold work steel suppliers comes from decades of commitment (since 1957) to quality, reliability and customer success.

Why Global Buyers Choose Toolman

Over the years, one pattern has stayed consistent: buyers don’t just want steel – they want predictability.

Toolman Special Steels delivers that by offering:

• Decades of metallurgical experience (since 1957)
• Export-ready logistics and documentation
• Technical guidance for toolmakers and OEMs
• Proven supply reliability across global markets

That’s why manufacturers in USA, Europe, Japan, Turkey and Southeast Asia continue to rely on us.

Closing Note

Precision industries don’t compromise and neither do we. Toolman Special Steels continues to deliver DIN 1.2379 with the consistency global manufacturers rely on.

 Write to us: indiatoolman@gmail.com
 Explore more: www.toolmansteels.com

Download the DIN 1.2379 Technical Datasheet →
(Includes chemical composition, mechanical properties, heat treatment curves & supply range)