AISI D6 / DIN 1.2436 / ISO X210CrW12 / JIS SKD2 Cold Work Tool Steel

Product Overview

What sets these cold work tool steels apart is their optimized alloy formulation, which delivers three core benefits critical to industrial performance: superior wear resistance, excellent toughness, and outstanding dimensional stability during heat treatment. Unlike lower-grade tool steels that may deform, lose edge sharpness, or fail under repeated cold-forming stress, AISI D6 / DIN 1.2436 / ISO X210CrW12 / JIS SKD2 retains its shape and functionality even in high-volume production environments. This makes it a top choice for industries such as automotive, aerospace, electronics, metal fabrication, and precision engineering—where tool longevity and part accuracy directly impact operational efficiency and cost-effectiveness.

Hunan Qilu Steel enhances these inherent properties through advanced manufacturing processes, including EF+LF+VD (Electric Arc Furnace + Ladle Furnace + Vacuum Degassing) or EAF+LF+VD+ESR (Electroslag Remelting) steelmaking, followed by precision forging and strict quality control. The result is a tool steel that meets or exceeds global standards, with uniform hardness distribution, minimal impurities, and consistent mechanical performance across every batch. Whether customers require hot-rolled bars, forged blocks, or custom-cut plates, Hunan Qilu Steel offers flexible supply options to match diverse application needs.

Product Features

Chemical Composition: The Foundation of Performance

The alloy makeup of AISI D6 / DIN 1.2436 / ISO X210CrW12 / JIS SKD2 is engineered to balance wear resistance, toughness, and machinability—key requirements for cold work tooling. Below is a detailed breakdown of each grade’s critical chemical elements (all values are percentage by weight, with maximum limits marked as “Max”):

AISI D6 (ASTM A681): Carbon (C) 2.00-2.20% (drives hardness and carbide formation), Silicon (Si) 0.20-0.40% (boosts tensile strength), Manganese (Mn) 0.20-0.40% (improves heat treatment response), Phosphorus (P) 0.030% Max (reduces brittleness), Sulfur (S) 0.030% Max (controls machinability), Chromium (Cr) 11.5-12.5% (enhances wear and corrosion resistance), Tungsten (W) 0.60-0.90% (reinforces edge retention at high temperatures).

DIN 1.2436 (DIN 17350): Carbon (C) 2.00-2.25%, Silicon (Si) 0.10-0.40%, Manganese (Mn) 0.15-0.45%, Phosphorus (P) 0.030% Max, Sulfur (S) 0.030% Max, Chromium (Cr) 11-12%, Tungsten (W) 0.60-0.80%. This grade aligns closely with AISI D6 but features slightly narrower Mn and Cr ranges, optimized for European manufacturing workflows.

ISO X210CrW12 (ISO 4957): Carbon (C) 2.00-2.30%, Silicon (Si) 0.10-0.40%, Manganese (Mn) 0.30-0.60%, Phosphorus (P) 0.030% Max, Sulfur (S) 0.030% Max, Chromium (Cr) 11-13%, Tungsten (W) 0.60-0.80%. The wider Cr range ensures compatibility with diverse cold-forming applications, from light stamping to heavy shearing.

JIS SKD2 (JIS G4404): Carbon (C) 2.00-2.30%, Silicon (Si) 0.10-0.40%, Manganese (Mn) 0.30-0.60%, Phosphorus (P) 0.030% Max, Sulfur (S) 0.030% Max, Chromium (Cr) 11-13%, Tungsten (W) 0.60-0.80%. This grade mirrors ISO X210CrW12, making it a preferred choice in Asian markets for precision tooling and mold-making.

The high carbon and chromium content forms hard, wear-resistant carbides, while tungsten strengthens these carbides to prevent edge dulling—even under repeated friction or impact. Low phosphorus and sulfur levels minimize brittleness, ensuring the steel can withstand the stress of cold forming without cracking.

Hardness & Hardenability: Consistent Strength Across Applications

AISI D6 / DIN 1.2436 / ISO X210CrW12 / JIS SKD2 exhibits exceptional hardness and hardenability, critical for maintaining tool performance in harsh cold work environments. Key hardness specifications include:

Annealed State (+A): Maximum hardness of HB255 (Brinell Hardness). Annealing—heating to 820-850℃, soaking, and slow furnace cooling—softens the steel for easy machining, allowing manufacturers to shape it into complex tool geometries (e.g., punching dies, shear blades) before final heat treatment.

Hardened & Tempered State (+HT): Minimum hardness of HRC62 (Rockwell Hardness C Scale). This is achieved through a precise heat treatment cycle: preheating to 820℃, heating to the quenching temperature of 960-980℃ (in a salt bath furnace for uniform heating), quenching in oil to lock in hardness, and tempering at 170-190℃ (followed by air cooling) to reduce internal stress while preserving strength.

The steel’s excellent hardenability ensures uniform hardness throughout its cross-section—even for thick tools (e.g., forged blocks up to 500mm thick)—eliminating weak spots that could lead to premature tool failure.

Supply Specifications: Flexible Options for Every Need

Hunan Qilu Steel offers AISI D6 / DIN 1.2436 / ISO X210CrW12 / JIS SKD2 in a range of product types, sizes, and surface finishes to match customer requirements. Key supply details include:

Product Types & Size Ranges:

Hot-Rolled Bars: Diameter (Φ) 10-190mm, Length 2000-5800mm

Hot-Forged Bars: Diameter (Φ) 200-600mm, Length 2000-5800mm

Hot-Rolled Plates/Sheets: Thickness (T) 10-60mm, Width (W) 310-810mm, Length 2000-5800mm

Hot-Forged Plates: Thickness (T) 70-250mm, Width (W) 310-810mm, Length 2000-5800mm

Hot-Forged Blocks: Thickness (T) 260-500mm, Width (W) 300-1000mm, Length 2000-5800mm

Surface Finishes & Tolerances:

Turned: Tolerance +0/+3mm, Straightness 1mm/1000mm Max

Milled: Tolerance +0/+3mm, Straightness 1mm/1000mm Max

Grinding (Best for Precision): Tolerance +0/+0.05mm, Straightness 1mm/1000mm Max

Polished (Best for Aesthetics): Tolerance +0/+0.05mm, Straightness 1mm/1000mm Max

Peeled (Best for Machinability): Tolerance +0/+0.1mm, Straightness 1mm/1000mm Max

Black Forged/Rolled (Economical): Tolerance +0/+5mm (Forged) / +0/+1mm (Rolled), Straightness 3mm/1000mm Max

Custom sizes and finishes are available upon request, ensuring customers get the exact material needed for their specific tooling projects.

Quality Assurance: Meeting Global Standards

To guarantee performance, AISI D6 / DIN 1.2436 / ISO X210CrW12 / JIS SKD2 undergoes rigorous quality control measures:

Ultrasonic Testing: Complies with EN10228-3 Class III or SEP 1921-84 D/D standards to detect internal defects (e.g., cracks, inclusions) that could compromise tool integrity.

Chemical Analysis: Every batch is tested for compliance with grade-specific composition requirements using advanced spectroscopy.

Mechanical Testing: Hardness tests (Brinell, Rockwell) and toughness tests (Charpy impact) ensure mechanical properties meet or exceed standards.

Applications

Cold Work Dies: Precision for Metal Forming

AISI D6 / DIN 1.2436 / ISO X210CrW12 / JIS SKD2 is ideal for cold work dies, where wear resistance and dimensional stability are non-negotiable. Key applications include:

Punching Dies: Used for creating holes or cutouts in metal sheets (e.g., automotive body panels, electronic components). The steel’s HRC62+ hardness and wear resistance ensure the die maintains sharp edges, reducing the need for frequent sharpening and minimizing production downtime.

Forming Dies: Suitable for bending, stretching, and flanging metal parts (e.g., HVAC ducts, appliance components). Its excellent dimensional stability during heat treatment prevents die deformation, ensuring consistent part quality across thousands of cycles.

Embossing Dies: Used for adding decorative or functional patterns to metal (e.g., coins, medals, nameplates). The steel’s uniform hardness ensures crisp, detailed embossing without pattern distortion.

Cold Upsetting Dies: Designed for shaping fasteners (e.g., bolts, nuts) by compressing metal at room temperature. The steel’s toughness resists the high compressive forces of upsetting, while its wear resistance extends die life.

Shear Knives: Used for cutting metal sheets, strips, or wires (e.g., steel coils, wire mesh). The steel’s edge retention and corrosion resistance (from chromium) ensure clean, precise cuts even in high-volume production.

Plastic Mold Components: Durability for Polymer Processing

While primarily a cold work tool steel, AISI D6 / DIN 1.2436 / ISO X210CrW12 / JIS SKD2 is also used for specialized plastic mold components that require high wear resistance:

Wear-Resistant Inserts: Installed in plastic molds (e.g., for glass-fiber reinforced plastics) to protect high-wear areas like ejector pins, guide bushings, and die nuts. The steel’s resistance to abrasion from glass fibers prevents premature insert failure, extending mold life.

Precision Gear Molds: Used for molding plastic gears (e.g., in toys, small appliances). Its high hardness ensures the mold retains fine gear teeth details, producing gears with accurate dimensions and smooth operation.

Precision Gauges & Parts: Accuracy for Quality Control

The steel’s uniform hardness and dimensional stability make it suitable for precision gauges and components that demand tight tolerances:

Gauges & Calibration Tools: Used for measuring part dimensions (e.g., snap gauges, plug gauges). The steel’s low thermal expansion and high hardness ensure long-term calibration accuracy, reducing the need for frequent recalibration.

Bearing Cold-Rolled Ring Dies: Used for manufacturing bearing rings by cold rolling metal blanks. The steel’s wear resistance ensures the die maintains the precise inner/outer diameters of bearing rings, critical for bearing performance.

Precision Fixtures: Used to hold parts during machining or inspection (e.g., CNC machine fixtures). Its rigidity and dimensional stability prevent fixture movement, ensuring accurate part positioning.

Specialized Industrial Tools: Versatility Across Sectors

Beyond traditional tooling, AISI D6 / DIN 1.2436 / ISO X210CrW12 / JIS SKD2 finds use in specialized applications:

Woodworking Tools: Planer knives and engraving knives benefit from the steel’s edge retention, ensuring smooth cuts and detailed engravings in hardwoods and softwoods.

Ceramic/Powder Metallurgy Molds: Used for compressing ceramic powders or metal powders into shapes (e.g., ceramic tiles, powder metallurgy gears). The steel’s wear resistance handles the abrasive nature of powders, while its toughness resists compressive forces.

Semiconductor Leadframe Dies: Used for punching leadframes (thin metal strips that connect semiconductors to circuit boards). The steel’s precision and wear resistance ensure clean, burr-free punches—critical for semiconductor reliability.

FAQ

1. What makes AISI D6 / DIN 1.2436 different from other cold work tool steels (e.g., AISI D2)?

AISI D6 / DIN 1.2436 is a medium-chromium (11-12.5%), tungsten-enhanced cold work tool steel, while AISI D2 is a high-chromium (11-13%) steel without tungsten. The key difference lies in toughness and edge retention: AISI D6 / DIN 1.2436 offers better toughness (ideal for applications with impact, like shear knives), while AISI D2 provides higher corrosion resistance. For cold forming, stamping, or upsetting—where toughness and wear resistance are equally important—AISI D6 / DIN 1.2436 is the more balanced choice. Additionally, AISI D6 / DIN 1.2436 has slightly lower carbon content than D2, making it easier to machine in the annealed state (HB255 Max vs. D2’s HB255 Max—but with better machinability due to tungsten’s effect on carbide distribution).

2. What heat treatment process is recommended for ISO X210CrW12 to achieve optimal performance?

For ISO X210CrW12, the recommended heat treatment cycle is tailored to maximize hardness and minimize stress:

Annealing: Heat to 820-850℃, soak for 2-4 hours (depending on part thickness), then cool slowly in the furnace (≤50℃ per hour) to reach HB255 Max—this softens the steel for machining.

Hardening: Preheat to 820℃ (to prevent thermal shock), then heat to 960-980℃ in a salt bath furnace (for uniform temperature distribution). Soak for 25 ± 1 minutes (per EN standards for cold work steels), then quench in oil (temperature ≤60℃) to lock in hardness.

Tempering: Heat to 170-190℃, soak for 60 minutes, then air cool. This step reduces internal stress while maintaining HRC62 Min hardness. For parts requiring slightly higher toughness, temper at 200-220℃ (note: this may reduce hardness to HRC60-61).

Avoid overheating above 980℃, as this can cause grain growth and reduce toughness.

3. What supply sizes are available for JIS SKD2 from Hunan Qilu Steel, and can custom sizes be ordered?

Hunan Qilu Steel offers JIS SKD2 in a wide range of standard sizes, including:

Hot-Rolled Bars: Φ10-190mm (length 2000-5800mm)

Hot-Forged Bars: Φ200-600mm (length 2000-5800mm)

Hot-Rolled Plates: T10-60mm × W310-810mm × L2000-5800mm

Hot-Forged Blocks: T260-500mm × W300-1000mm × L2000-5800mm

Custom sizes (e.g., shorter lengths, thicker plates, or non-standard diameters) are available upon request. Lead times for custom sizes vary based on quantity and complexity—typically 2-4 weeks for small batches (≤5 tons) and 4-6 weeks for large batches (>5 tons). All custom orders include ultrasonic testing (EN10228-3 Class III) to ensure quality.

4. Is DIN 1.2436 suitable for food-grade or medical applications?

No, DIN 1.2436 is not recommended for food-grade or medical applications. While it contains chromium (11-12%) for basic corrosion resistance, it lacks the higher chromium content (≥16%) and low carbon levels required for food-grade (e.g., AISI 430) or medical-grade (e.g., AISI 316L) stainless steels. Additionally, DIN 1.2436 may contain trace impurities (e.g., sulfur up to 0.030%) that are not compliant with food or medical safety standards (e.g., FDA, EU 10/2011). For food/medical tooling, Hunan Qilu Steel recommends stainless steel grades like AISI 430 (food-grade) or AISI 316L (medical-grade).

5. How does Hunan Qilu Steel ensure the quality of AISI D6 shipments, and what certifications are provided?

Hunan Qilu Steel follows a strict quality control process for AISI D6 to meet global standards:

Steelmaking: Uses EF+LF+VD or EAF+LF+VD+ESR processes to reduce impurities (e.g., oxygen, nitrogen) and ensure uniform composition.

Testing: Every batch undergoes:

Chemical analysis (via optical emission spectroscopy) to verify compliance with ASTM A681 standards.

Hardness testing (Brinell for annealed parts, Rockwell for hardened parts) to confirm HB255 Max (annealed) or HRC62 Min (hardened).

Ultrasonic testing (EN10228-3 Class III) to detect internal defects.

Certifications: Each shipment includes a Certificate of Quality (CoQ) that documents chemical composition, mechanical properties, test results, and batch numbers. For customers requiring additional certifications (e.g., ISO 9001, CE), Hunan Qilu Steel can provide these upon request—all certifications are third-party verified for transparency.

1: Steel equivalent

2: Chemical composition

3: Surface hardness and hardenability.

4: Supply size & Tolerance & Stock size

For 1.2436 steel, because we don’t use them in domestic market, so there is no stocks for that material.

5: Ultrasonic Test    

EN10228-3 class III or Sep 1921-84 D/D

6：Steel making & Forging processing

1): Steel making process:

  EF+LF+VD

  EAF+LF+VD

  EF+LF+VD+ESR

  EAF+LF+VD+ESR

2): Forging processing:  

Put the 1.2436 ingot into the furnace and pre-heat to 650-700℃

Continue heating the ingot to initial temperature: 1050-1100℃

Forge the ingot, forging temperature should be not less than 850℃

Cooling in the sand slowly or in the furnace

7: Heat treatment

1): Annealed:

Heat 1.2436 steel to 820-850℃ in the furnace

Soak at this temperature in the furnace

Cooling in the furnace slowly

2): Quenching and tempering:  

Preheat Temperature: 820℃

Heat 1.2436 steel to 960-980℃ in the salt bath furnace

Soak at this temperature in the furnace

Quench in oil

Temper steel at 170-190℃ in the furnace

Take out from furnace and cool in the air.

Above curve in figure is just a rough guide to the tempering behaviour of steels. When applying the curves for an estimation of the hardness which can be expected in quenched and tempered tools, it should be taken into account that the optimum heat-treatment conditions for the tools are not necessarily identical with those specified for the test pieces.

The heating time of test pieces in a salt batch shall be as give in below table:

Total heating time of test pieces in a salt bath

If the test pieces are not heated in a salt batch, the heating time must be extended accordingly, and the times for heating give above are not valid for thicker tools.

8：Application

1.2436 is a high-carbon, medium-chromium cold work die steel with excellent wear resistance, toughness and dimensional stability, and is widely used in the following areas:

1. Cold Work Dies

1) Punching Dies (Punching, Drop Dies)

2) Forming Dies (Bending, Stretching, Flanging Dies)

3) Embossing Dies (Coins, Medals, Precision Embossing)

4) Cold Upsetting Dies (Bolts, Nuts Forming)

5) Shear Knives (Precision Shear Blades, Slitting Knives)

2. Plastic Molds

1) Wear-resistant inserts (die nuts, ejector pins, guide bushings)

2) Glass-fiber reinforced plastic molds

3) Precision gear molds

3. Gauges and Precision Parts

1) Gauges, card boards

2) Bearing rings cold rolled ring die

3) Precision fixtures and guiding parts

4. Other special applications

1) Woodworking tools (planer knives, engraving knives)

2) Ceramics / powder metallurgy compression molds

3) Semiconductor leadframe punching dies