D2 Steel

D2 tool steel offers superior wear resistance, compressive strength, and dimensional stability—ideal for high-precision trimming, blanking, and high-cycle die casting tooling applications.

Introduction to D2 Steel

D2 is a high-carbon, high-chromium cold-work tool steel offering exceptional wear resistance, compressive strength, and dimensional stability. Its rich alloy composition enables long die life under high-cycle, high-abrasion conditions. It is ideal for blanking dies, trimming tools, and inserts used in aluminum and zinc die casting.

At Neway Die Casting, D2 is selected for tooling components exposed to intense wear, ensuring consistent edge retention, minimal deformation, and reduced downtime across high-volume production environments.

D2 Steel Chemical Composition (Typical, per ASTM A681)

Element	Weight %	Function
Chromium (Cr)	11.0–13.0	Primary contributor to wear and corrosion resistance
Carbon (C)	1.40–1.60	Provides high hardness and compressive strength
Molybdenum (Mo)	0.7–1.2	Enhances secondary hardening and toughness
Vanadium (V)	0.1–0.3	Improves wear resistance and grain refinement
Manganese (Mn)	0.2–0.6	Enhances hardenability
Silicon (Si)	0.1–0.6	Improves temper resistance
Iron (Fe)	Balance	Base matrix

The high chromium content enables secondary hardening and provides resistance to softening during tempering, even at elevated temperatures.

Physical Properties of D2 Tool Steel

Property	Value & Unit
Density	~7.7 g/cm³
Thermal Conductivity	20–22 W/m·K
Specific Heat Capacity	~460 J/kg·K
Coefficient of Thermal Expansion	10.5–11.2 µm/m·°C
Electrical Resistivity	~0.6 µΩ·m
Decarb-Free Depth (hardened)	≥ 2 mm

These properties support dimensional stability in post-heat treatment operations, even with fine-featured components.

Mechanical Properties (Heat Treated to 58–62 HRC)

Property	Typical Value & Unit
Tensile Strength	1900–2100 MPa
Yield Strength	~1600 MPa
Hardness	58–62 HRC
Compressive Strength	>2300 MPa
Impact Toughness (Charpy)	10–20 J
Modulus of Elasticity	~210 GPa

D2 achieves very high hardness and edge retention while maintaining structural integrity under high-pressure contact in die trims or punches.

Die Casting and Tooling Suitability

D2 is particularly suitable for:

Edge-forming inserts and trimming dies
Cutting punches for flash removal in zinc and aluminum die castings
Guide pins and wear strips for mass production tooling
Sliders and bushings operating under abrasive contact
Blanking or shearing dies where minimal wear is acceptable over long cycles

Its abrasion resistance makes it ideal for post-casting operations, especially in automated die trimming systems.

Common Applications

Thanks to its resistance to galling, abrasion, and high compressive stress, D2 is widely used in:

Die casting post-process stations for trimming and blanking
Fine edge punches and high-pressure inserts
Wear-resistant dowels, bushings, and fixture parts
Cold-forming and stamping dies
Injection mold gates exposed to high-fiber-fill polymers

Machining Challenges and Solutions

Due to its hardness and chromium content, D2 is more difficult to machine than A2 or P20:

Annealed condition (~225 HB) is optimal for rough machining
Requires high-rigidity setups and coated carbide tooling
Post-hardening operations include grinding and EDM only

At Neway, D2 is machined with:

CNC-controlled roughing and finishing in staged heat treatment
Wire EDM to ensure dimensional accuracy on hardened profiles
Final tolerances within ±0.01 mm and surface finish down to Ra 0.6 µm

Surface Treatment Compatibility

D2’s alloy matrix accepts multiple hardening and coating treatments:

Nitriding to add a tough surface layer without reducing core strength
PVD coatings (TiCN, AlTiN) to further resist galling and friction
Cryogenic treatment to stabilize martensitic structure and reduce retained austenite

These enhancements extend die life especially in automated or unattended die cutting environments.