Choosing the wrong tool steel for a mold or die is one of the most expensive mistakes a toolroom can make. A die that cracks at 30,000 shots instead of 300,000 means lost production, unplanned downtime, and a replacement order that costs far more than the steel itself-21. Yet many procurement teams still default to "whatever grade we used last time" or "whatever the local stockist has on the shelf."
This guide compares the three most commonly sourced tool steel grades H13, D2, and P20 from a specification and sourcing perspective. It is written for die engineers, toolroom managers, and procurement teams who buy tool steel from Chinese mills and distributors. All chemistry and property data below reflects standard mill-published values; actual values must be confirmed against the mill test certificate for each heat.
Sichuan Liaofu Special Steel Trading Co., Ltd. stocks and supplies these grades in round bar, flat bar, and plate form, sourced from approved Chinese mills including Fushun Special Steel and Baoshan Iron and Steel. We are a trader, not a mill, and every shipment includes the original mill test certificate.
Why Tool Steel Grade Selection Determines Die Life
Tool steel selection is an application-first decision, not a strength-first decision-21. Three properties are in constant tension: wear resistance, toughness, and red hardness (thermal stability). Improving one almost always means sacrificing another. H13, D2, and P20 each occupy a distinct position in this trade-off space, and each is optimised for a different working environment.
The correct approach is to define the operating conditions - peak temperature, impact load, cooling method, and wear mechanism - and then select the grade that matches those conditions at the lowest total cost.
Chemical Composition and Hardness
H13 (DIN 1.2344, JIS SKD61, GB 4Cr5MoSiV1) is a chromium hot-work tool steel. Typical chemistry:
| Element | Range (wt.%) |
|---|---|
| C | 0.32 – 0.45 |
| Cr | 4.75 – 5.50 |
| Mo | 1.10 – 1.75 |
| V | 0.80 – 1.20 |
| Si | 0.80 – 1.20 |
Standard hardness range is 48–52 HRC after quenching and double tempering. H13 maintains hardness and toughness at service temperatures up to approximately 500°C and resists thermal shock and heat checking-21.
When to Choose H13
H13 is the global workhorse for hot-work applications. Roughly 70% of international hot-work tool steel orders adopt H13 series materials-3. Typical applications include:
Aluminium die-casting dies
Hot forging dies
Extrusion dies and stems
Hot shear blades
For longer die life in demanding die-casting operations, an ESR (electroslag remelted) grade of H13 offers higher purity and improved thermal fatigue resistance-3. For high-toughness, crack-sensitive applications, H11 (1.2343) may be preferred over H13 due to its better mechanical toughness and thermal shock resistance-3.
The Cold-Work Wear Specialist
Chemical Composition and Hardness
D2 (DIN 1.2379, JIS SKD11, GB Cr12MoV) is a high-carbon, high-chromium cold-work tool steel. Typical chemistry:
| Element | Range (wt.%) |
|---|---|
| C | 1.40 – 1.60 |
| Cr | 11.0 – 13.0 |
| Mo | 0.70 – 1.20 |
| V | 0.90 – 1.10 |
D2 achieves 58–62 HRC after hardening, giving it excellent wear resistance for cold-cutting and stamping operations-21. However, its high carbide content makes it more brittle than H13 and more difficult to machine-.
When to Choose D2
D2 is the correct choice when the die operates at or near room temperature and wear is the dominant failure mode:
Blanking and stamping dies
Shear blades
Cold-forming rolls
Wear inserts and wear plates
For applications involving impact loads on thin materials, DC53 (an improved cold-work grade with higher toughness than D2) or powder metallurgy (PM) steels may offer better resistance to chipping and galling.
The Plastic Mold Workhorse
Chemical Composition and Hardness
P20 (DIN 1.2311) is a pre-hardened plastic mold steel. Typical chemistry:
| Element | Range (wt.%) |
|---|---|
| C | 0.28 – 0.40 |
| Cr | 1.40 – 2.00 |
| Mn | 0.60 – 1.50 |
| Mo | 0.20 – 0.55 |
P20 is delivered pre-hardened at approximately 28–34 HRC. This means no post-machining heat treatment is required, eliminating distortion risk and the possibility of cracking a finished cavity during quench-21.
When to Choose P20
P20 dominates plastic injection mold work because of its machinability, polishability, and moderate cost:
Injection mold cores and cavities
Mold bases
Compression and RIM tooling
Low-volume zinc die casting
P20 is not suitable for high-temperature or high-wear service. Above approximately 400 mm section thickness, through-hardness becomes inconsistent-21. For glass-fibre-reinforced plastics or high-wear inserts, H13 or D2 would be more appropriate.
Quick Comparison Table
| Property | P20 | H13 | D2 |
|---|---|---|---|
| Family | Plastic mold | Hot work | Cold work |
| Typical hardness (HRC) | 28–34 | 48–52 | 58–62 |
| Working temperature | < 400°C | < 500°C | Room temp |
| Wear resistance | Moderate | Good | Excellent |
| Toughness | Good | Excellent | Moderate |
| Machinability | Excellent | Good | Difficult |
| Typical application | Injection molds | Die casting, forging | Stamping, blanking |
Common Grade Selection Mistakes and How to Avoid Them
Mistake 1: Using D2 for a die that sees thermal cycling. D2 is a cold-work grade. It will lose hardness and crack under repeated heating and cooling.
Mistake 2: Using H13 for cold stamping. At room temperature, H13's 48–52 HRC is overkill-soft for wear and costs more than D2. It earns its premium only when the die runs hot-21.
Mistake 3: Assuming "pre-hardened P20" means no further treatment is needed. P20 can be nitrided for higher surface hardness if wear is a concern. Discuss nitriding with your heat treater before final machining.
Mistake 4: Ignoring the mill certificate. Tool steel with correct chemistry can still fail if the heat treatment condition or cleanliness (inclusion rating) is not as specified. Always verify the MTC before accepting material.
Sourcing Tool Steel from a Stocking Distributor
Sichuan Liaofu Special Steel Trading Co., Ltd. stocks H13, D2, P20, and other common tool steel grades in round bar, flat bar, and plate form. We source from approved Chinese mills and provide:
Original mill test certificates with every shipment
Cutting-to-size service for trial and production quantities
Export packaging and documentation
Support for small trial orders and mixed-grade shipments
We are a trader, not a mill. Our value is flexibility, documentation, and export service.
FAQ
Q: What details should I include in an RFQ for H13, D2, or P20?
A: Grade, standard, size, delivery condition, quantity, and application. This helps us confirm stock and quote accurately.
Q: Do you supply H11 as well as H13?
A: Yes. H11 is available on request, while H13 is the more commonly stocked grade.
Q: What is the main difference between D2 and D3?
A: D3 has higher carbon and chromium, giving better wear resistance but lower toughness than D2.
Q: Can P20 be nitrided after machining?
A: Yes. Nitriding increases surface hardness. Confirm the process with your heat treater before final machining.
Q: Can you cut H13 or D2 plate to my required size?
A: Yes. We offer cut-to-size service, and each piece is marked with its heat number.
Q: Do you provide the original mill MTC with every shipment?
A: Yes. Every shipment includes the original mill test certificate with full heat traceability.
Q: Do you support mixed-grade orders in one shipment?
A: Yes. H13, D2, P20, and other grades can be combined in one shipment.
Q: What export packaging do you use?
A: Wooden crates, steel strapping, moisture barriers, and shipping marks.
Q: Are you a steel mill or a trading company?
A: We are a trading company. We do not melt steel or operate a laboratory. All data comes from the producing mill.