Casting tool steels are the backbone of modern manufacturing, enabling the production of durable molds, dies, and cutting tools. These materials must withstand extreme conditions, including high temperatures, mechanical stress, and wear. Below, we explore the top 10 tool steels for casting, their unique properties, and applications, backed by technical insights and industry data.
1. H13 Steel
I find H13 steel is a great choice for casting. It has excellent hardness when hot. It also resists wear from quick temperature changes well. In my experience, this chromium-molybdenum hot work steel stays hard. It can do this even at high temperatures, up to 600°C.H13 is a top choice among tool steels for casting. It offers a good mix of being durable, tough, and stable at high temperatures. I believe these features make it a money-saving and dependable option for tough industrial jobs.
Key Features of H13 Tool Steel
Stays Hard When Hot: It keeps its strength and hardness even after many heating and cooling cycles. I’ve seen this consistently.
Resists Heat Cracking: It’s very good at stopping cracks when temperatures change fast. This is a key benefit I often point out.
Improved Wear Resistance: When you apply post-casting heat treatment, like quenching and tempering, its ability to resist wear improves. I suggest this step for better performance.
Common Applications
Die Casting Dies: I often see H13 used for making dies. These dies need to handle strong heat and pressure.
Hot Stamping Tools: It’s a good fit for tools that go through extreme heating and cooling cycles.
Plastic Injection Molds: I recommend it for mold parts that get very hot.
Casting Tips for H13 Tool Steel
I recommend treating the steel with heat after you cast it. Based on my experience, proper quenching and tempering greatly improve how well the tool resists wear. This also helps the tool last longer.
2. H21 Steel: Its Features, Uses, and How It Performs in Casting
I find H21 steel to be a top choice for tungsten hot work steel in casting. It contains 9.5% tungsten. Because of this, it resists softening even when things get very hot during use. It also maintains good toughness. From what I’ve seen, H21 is valuable because, unlike grades with more tungsten, you can cool it with water. This is true if the die design allows for it. This feature really helps manage heat during casting jobs.
Key Mechanical Properties I Look For in H21 Tool Steel
| Property | Value |
|---|---|
| Hardness | 40.0–55.0 Rockwell C |
| Bulk Modulus | 140 GPa (20,300 ksi) |
| Shear Modulus | 80.0 GPa (11,600 ksi) |
| Poisson’s Ratio (at 25°C) | 0.27–0.30 |
| Elastic Modulus | 190–210 GPa |
I believe these figures mean you can expect strong and stable results when using it for casting at high temperatures.
Where I See H21 Tool Steel Used in Casting
I often suggest H21 for casting work. This is particularly true if the steel will face high temperatures repeatedly. It’s also good for situations with tough mechanical demands. Some common uses I’ve seen are:Mandrels,Hot blanking dies,Hot punches,Drying shear blades,Hot trim dies,Extrusion dies,Dummy blocks,Piercer points,Gripper dies.
Based on my experience, H21 performs very well in die casting molds and dies. These applications require parts that last long and are tough. I’ve noticed it handles cooling at the work site and fast temperature changes better than most other hot-work tool steels.
Why I Recommend H21 Tool Steel for Casting
I suggest using H21 if your casting process involves very high working temperatures. It’s also a good pick if you need a tool steel that won’t soften or change shape under stress. In my view, H21 is a dependable and economical selection. I find its combination of hardness, toughness, and resistance to wear from heat makes it a standard choice for hot work tasks and complicated die designs. For the best outcomes, I recommend that your die or tool includes water-cooling features, if possible. This allows you to fully use H21’s compatibility with water cooling. I believe this approach will also extend the life of your tool.
3.D2 Steel: A Strong Choice for Casting and Tooling
I find D2 steel is excellent when you need very hard steel that resists wear. It’s a high-carbon, high-chromium steel that air hardens. Many people use it for die casting. They also use it to make tough cutting tools. I think its strong performance is great for demanding jobs. It works well where other steels might fail quickly.
Key Mechanical Properties and What They Mean
| Key Mechanical Properties | Value and Explanation |
|---|---|
| Hardness (Rockwell C) | 58–62 HRC (Heat treatment can achieve 60–62 HRC, making D2 one of the hardest tool steels). |
| Tensile Strength | 260,000 psi (approximately 1,793 MPa) |
| Yield Strength | 240,000 psi (approximately 1,655 MPa) |
| Elastic Modulus | 207 GPa |
| Poisson’s Ratio | 0.27–0.30 |
| Density | 7,700 kg/m³ |
I believe these numbers show D2 can take a lot of force. It keeps its shape and qualities even after many uses.
Where I Suggest Using D2 Tool Steel
From my experience, D2 is great for jobs where tools must stay sharp and not wear out easily. I often see it used for these casting and toolmaking tasks.
Cold work dies & punches: I’ve found these tools last longer because D2’s surface wears slowly.
Shear blades & slitters: D2 keeps a sharp edge, even when cutting materials that can wear things down.
Forming and blanking dies: This steel resists wear well, so tools last longer.
Plastic molds: I think it’s very good for molds used many times or for plastics that cause wear.
My Tips for Machining and Casting
Machining Advice: D2 is hard, so it’s not easy to machine. I always recommend using carbide tools for cutting and shaping D2 parts. This helps tools last longer and gives a better finish.
Heat Treatment: To get the best hardness (HRC 60–62), you must heat treat it carefully. I believe this step is very important to get the material’s full strength and wear resistance.
4. A2 Tool Steel: Why I Recommend It for Hardness, Stability, and Precision Casting
I often work with A2 tool steel. It’s an air-hardening, medium-alloy, cold work tool steel. Most people know it as a 5% chromium steel. For casting, I find A2 very useful because it has a good mix of qualities. It offers hardness, keeps its shape well after heat treatment, and stands up to wear pretty well.
Key Features and Benefits I See in A2 Tool Steel
Keeps Its Shape Very Well: I’ve seen that after heat treatment, A2 tool steel does a great job holding exact shapes and sizes. This is why I recommend it when you need the final product to be very accurate.
Good Wear Resistance: A2 might not resist wear as much as some high-chromium steels. However, in my experience, it keeps a solid edge. This helps tools last longer in tough jobs.
Easy to Machine: I find A2 easier to machine than high-chromium steels like D2. This can cut down production time and costs. This is a big help when you’re making complex dies.
Good Balance of Toughness and Hardness: In my view, A2 tool steel offers a great balance. It’s tough enough to handle impacts. It also gives you the hardness you need for good performance.
Where I Often Use A2 Tool Steel in Casting
Based on my experience, I find A2 is a solid choice for many cold work and precision tools. I’ve used it for:Blanking tools and punch dies,Forming, stamping, and trim dies,Gauges and shear blades,Thread rolling and extrusion dies,Mandrels, master hubs, slitters,Precision tools where you need parts to fit perfectly and not change shape.
5. S7 Tool Steel: Shock Resistance and Toughness in Casting
I find S7 tool steel excellent due to its great shock resistance and high toughness. I often recommend it for casting tasks. This is when tools need to handle heavy impacts and repeated stress without cracking. I’ve seen it work well for both hot and cold work situations where other tool steels might fail.
Essential Data for S7 Tool Steel
| Property | Value / Range |
|---|---|
| Density | 7.83 g/cm³ (0.283 lb/in³) |
| Hardness (HRC) | 48–58 (optimum: 54–56) |
| Yield Strength | 235 ksi (@500°F temper) |
| Charpy Impact Value | 16.9 J |
| Modulus of Elasticity | 207 GPa |
| Critical Temp (AC1) | 785°C (1445°F) |
Typical Casting and Tooling Applications I Recommend for S7
I recommend S7 for cold work punches and dies. These tools must withstand heavy impact.
I also suggest it for shear blades. These often operate under tough workloads.
It’s good for chisels and hammers. For these, resistance to breakage is very important.
I use it for die casting inserts. These inserts endure rapid temperature cycles.
I also like it for plastic mold tools that receive repeated impact.
Why S7 Tool Steel Is My Go-To for High Impact Casting
In my experience, S7 tool steel offers peace of mind. This is particularly true when I am concerned about a tool cracking or failing under a sudden load. After hardening, it keeps its shape well. This means parts stay reliable over a long time. I think S7 is a cost-effective choice for high-impact, high-duty casting tools. It leads to longer tool life and means you’ll need less maintenance. If your project involves impact, thermal shock, and you need consistent performance, I always suggest you consider S7.
6. M2 Tool Steel: My Go-To High-Speed Steel for Casting and Toolmaking
I often choose M2 tool steel for casting parts. These parts need to resist wear and be tough. M2 is a versatile molybdenum high-speed steel (HSS). I like it because it offers a good mix of strength, long life, and heat resistance. From my perspective, this makes M2 a top choice for casting tools. These tools deal with a lot of friction and heat.
Key Properties and Mechanical Data of M2 Tool Steel
I am impressed by M2. It stays hard even at high temperatures. This is often called “red hardness.” I find this quality very important for cutting and forming tools. These tools tend to heat up after many uses. In my experience with M2 for casting, the tools show reliable strength, even as they get hot.
Main Uses for M2 Tool Steel in Casting
Based on my experience, I often recommend M2 for:
Cutting tools such as drills, milling cutters, and reamers. These tools must work well at high speeds.
Broaches, knives, and taps. For these, I prioritize sharpness and long life.
Rolling racks, thread roll dies, and mandrels. These parts face constant wear and impact.
Cold work punches and dies. I find these useful where both hardness and toughness matter significantly.
I’ve seen M2 replace T1 steel in many workshops. I’ve noticed this because M2 offers advantages over T1. It has about 50% more bending strength. It’s also tougher and shows greater thermo-plasticity. I believe these features help tools last longer. They can handle tough jobs and long work periods.
7. A6 Tool Steel: Great for Stable and Tough Precision Castings
I find A6 tool steel to be an excellent choice. It’s a medium-alloy, air-hardening cold work tool steel. I recommend it for casting projects where you need tools that keep their shape and are tough. What I like about it is its ability to harden deeply. It also changes very little in size during heat treatment. This really makes it stand out from other tool steels when you need precise work.
Mechanical Data
| Mechanical Data | Value / Range |
|---|---|
| Hardness (Rockwell C) | 61–62 |
| Elastic Modulus | 200 GPa (29,000 ksi) |
| Bulk Modulus | 140–160 GPa (20,300–23,200 ksi) |
| Shear Modulus | 77.0 GPa (11,200 ksi) |
| Poisson’s Ratio | 0.3 |
| Machinability | 65% compared to standard carbon tool steel |
Where I Suggest Using A6 Tool Steel in Casting
I recommend A6 tool steel for casting. I suggest using it when you need tools that demand exact sizes and good toughness. In my experience, and looking at how it’s used in the market, I see it in:
Large blanking and forming dies that need to stay very stable.
Trimming and coining dies for sharp, clean results.
Heavy-duty punches and shear blades built to last.
Precision tools and plastic molds where keeping exact sizes is key.
Spindles, mandrels, and stripper plates.
Master hubs, retaining rings, rim rolls, feed fingers.
Notching dies and bending tools that take a lot of impact.
8. 1.2367 Tool Steel: High-Performance Hot Work Tool Steel for Casting
In my experience, 1.2367 tool steel (also X38CrMoV5-3) is excellent for casting jobs. These jobs need great heat resistance and toughness. This alloy is a chromium-molybdenum-vanadium steel. It is made for hot work. I’ve seen its high thermal fatigue resistance makes a big difference. This resistance is very important. It helps when tools go through many heating and cooling cycles, like in casting.
Why I Recommend 1.2367 Tool Steel for Casting
I recommend 1.2367 for tough casting jobs. A big reason is the advanced ESR (Electro-Slag Remelting) process used to make it. This process refines the steel’s grain structure. It also boosts its purity and makes it very clean. This results in better strength and performance. I’ve seen that this high refinement gives me tools and dies. These tools are more consistent. They are less likely to crack. This makes them more reliable for long production runs.
Key Applications Where I Find 1.2367 Excels
| Application Category | Specific Uses and Examples |
|---|---|
| Light Alloy Die Casting Dies | Aluminum, Zamak, magnesium, and brass die casting |
| Injection Molding Dies | Thermoset and thermoplastic injection molds |
| Extrusion Tooling Parts | Liners, mandrels, pressure pads, stems, and dies |
| Forging and Hot Stamping | Light and heavy metal forging dies, hot stamping tools |
| Hot Rolling Rolls | Wear and thermal shock-resistant hot rolling rolls |
| Repeated High-Heat Cycle Tools | Closed dies, punches, stamps, and jaws used in continuous high-temperature operations |
9. 1.2363 Tool Steel: Versatile Cold Work Steel for Precision Casting
I consider 1.2363 tool steel (also known as A2, X100CrMoV5, SKD12, or BA2) a dependable option for casting tools. These tools need good toughness and precise dimensions. From my experience, this air-hardening, 5% chromium cold work steel has excellent qualities. I think it’s great for tough jobs in the tooling and casting fields.
Positioning and Advantages in Tool Steel Casting
From my perspective, 1.2363 fits nicely between 1.2842 and 1.2379 tool steels in terms of performance. In my opinion, compared to 1.2842, it resists wear better. I also find it hardens more reliably in thick sections. When put against 1.2379, I see it has better toughness and is easier to machine. I believe this helps a lot when making complex or detailed cast tools.
| Advantages in Casting | Explanation |
|---|---|
| Suitable for Large-Mass Tools | Air-hardening property makes it more reliable than oil- or water-hardening steels for thick castings, reducing the risk of deformation or cracking. |
| Stable Precision | Maintains shape well, ensuring finished castings remain accurate and less prone to distortion during heat treatment. |
| Balanced Machinability and Wear Resistance | Enables efficient production of durable and detailed tools such as molds or dies |
10.H11 (AISI/UNS T20811)
I find H11 steel really impressive. It shows great impact toughness and resilience.This steel is a 5% chromium hot work tool steel. It has a lower carbon content.I recommend it for tough casting situations. In these jobs, your tools must be durable and tough.
Key Properties and Technical Data of H11 Tool Steel
| Key Properties and Technical Data of H11 Tool Steel | Value / Range |
|---|---|
| Density | 7.81 g/cc (0.282 lb/in³) |
| Melting Point | 1427°C (2600°F) |
| Tensile Strength | 1792 MPa (260 ksi) |
| Thermal Expansion (20–100°C) | 11.9 x 10⁻⁶/°C (6.63 µin/in°F) |
| Thermal Conductivity (100°C) | 42.2 W/mK (292.9 in/hr.ft².°F) |
| Modulus of Elasticity | – At 204°C (400°F): 190 GPa (27,500 ksi) – At 538°C (1000°F): 159 GPa (23,000 ksi) |
| Performance | Maintains ductility and toughness at strength levels up to 275 ksi |
Best Uses for H11 Tool Steel in Casting
Hot tooling: I suggest using H11 for hot tooling. Your die casting dies, forging dies, and hot shear blades will benefit. Hot gripper dies and different extrusion tools also get good results. This is because H11 resists impacts well and stays stable at high temperatures.
Structural applications: I often select H11 for components that face high stress. For instance, aircraft landing gear is a good example. These parts need to be tough. They also must stay strong at high temperatures.
Other uses: I also find it useful for hot punches. It works for other tools too. These tools need to be hard when hot and resist shocks effectively.
In my experience, H11 tool steel is a very reliable choice. I recommend it if your casting tools will encounter strong impacts or rapid temperature changes. It also handles structural stress effectively. If toughness is something you cannot sacrifice, H11 is a great option.
summary
I’ve explored these 10 tool steels. From my experience, I know choosing the right one is key for successful casting. Each steel offers something unique. I’ve seen H13 excel with heat. S7 is incredibly tough, in my view. And I recommend D2 when you need high wear resistance. Working with these materials for years, I’ve learned something important. You get the best results by matching the steel to your specific job requirements. This is what I’ve consistently found. I encourage you to understand these different steels. Knowing them helps you make choices that extend tool life and lower costs. Plus, I’ve seen it lead to better quality castings. To me, selecting the right tool steel isn’t just picking a material. I see it as a direct investment in your project’s success.