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P20Ni | 1.2738 | P20+Ni Tool Steel For Plastic Mold
- John
SteelPro Group specialize in the production of high-quality Tool Steel. Our range includes 1.2738 steel, P20Ni hot-rolled or forged bars, plates, and blocks. With years of expertise, we provide reliable products to meet your requirements.
What Is 1.2738 Tool Steel?
1.2738 steel is a plastic mold steel. It contains Cr-Ni-Mo as alloying elements offering superior strength, hardness, and toughness. It is known for excellent machinability, outstanding polishability, and wear resistance compared to similar grades like 1.2311. This makes it ideal for large plastic molds, deep engraving, and molds subjected to high impact, particularly in the core areas.
We supply 1.2738 tool steel in a pre-hardened condition with a hardness range of 280 to 325 HB. It is ideal for nitriding and chrome plating for enhanced performance.
What Is The Equivalent of 1.2738 Steel?
1.2738 steel, also known as P20+Ni or P20Ni, has several international equivalents across various standards. Below is a list of its counterparts:
| Standard | Equivalent Grade |
| GB | 3Cr2MnNiMo |
| ASTM/AISI | P20Ni |
| ISO | 40CrMnNiMo 8-6-4 |
| DIN | 1.2738 |
| JIS | PDS5S steel |
| ISC | T25553 |
1.2738 Tool Steel Products Forms And Supply Range
We offer 1.2738 steel in bars, plates, blocks, and rounds in various sizes, with custom sizing available. Our products meet international standards like GB/T 1299 and ASTM A681, ensuring precise dimensions and high quality.
| Product Form | Dimension Range (Metric) | Dimension Range (Metric) |
| Bars | Diameter: 20 mm to 500 mm | Diameter: 0.8 in to 20 in |
| Length: 3,000 mm to 6,000 mm | Length: 118 in to 236 in | |
| Plates | Thickness: 10 mm to 300 mm | Thickness: 0.4 in to 12 in |
| Width: 200 mm to 2,500 mm | Width: 8 in to 98 in | |
| Length: 1,000 mm to 6,000 mm | Length: 39 in to 236 in | |
| Blocks | Thickness: 50 mm to 300 mm | Thickness: 2 in to 12 in |
| Width: 200 mm to 1,500 mm | Width: 8 in to 59 in | |
| Length: 300 mm to 2,500 mm | Length: 12 in to 98 in | |
| Rounds | Diameter: 30 mm to 500 mm | Diameter: 1.2 in to 20 in |
| Length: 3,000 mm to 6,000 mm | Length: 118 in to 236 in |
1.2738 Tool Steel Chemical Composition
| Element | Composition |
| Carbon (C) | 0.35 – 0.45 |
| Silicon (Si) | 0.2 – 0.4 |
| Manganese (Mn) | 1.3 – 1.6 |
| Phosphorus (P) | ≤0.03 |
| Sulfur (S) | ≤0.03 |
| Chromium (Cr) | 1.8 – 2.1 |
| Nickel (Ni) | 0.9 – 1.2 |
| Molybdenum (Mo) | 0.15 – 0.25 |
1.2738 Tool Steel Physical Properties
| Property | Metric Value | Imperial Value |
| Density | 7.85 g/cm³ | 0.284 lb/in³ |
| Thermal Conductivity | 29.0 W/m·K | 16.78 BTU·in/hr·ft²·°F |
| Specific Heat Capacity | 460 J/kg·K | 0.11 BTU/lb·°F |
| Thermal Expansion Coefficient | 11.5 µm/m·K | 6.39 x 10⁻⁶ in/in·°F |
| Electrical Resistivity | 0.52 µΩ·cm | 0.52 µΩ·in |
1.2738 Tool Steel Mechanical Properties
| Property | Metric Value | Imperial Value |
| Tensile Strength | 750 – 950 MPa | 108,000 – 137,750 psi |
| Yield Strength | 500 – 700 MPa | 72,500 – 101,500 psi |
| Elongation at Break | ≥12% | ≥12% |
| Hardness (soft annealed) | <235 HB | <235 HB |
| Hardness (hardened and tempered) | <51 HRC | <51 HRC |
| Impact Toughness (Charpy) | 25 J | 18.5 ft·lbf |
| Modulus of Resilience | 10.2 J/mm³ | 0.18 ft·lbf/in³ |
| Poisson’s Ratio | 0.28 | 0.28 |
Heat Treatment of 1.2738 Tool Steel
We supply 1.2312 steel in a pre-hardened state, so additional heat treatment is generally not needed. However, if you’re using it in high-stress applications or need higher hardness, we recommend tempering or stress relief to optimize performance.
Annealing
To soften 1.2312 steel, heat it to around 710°C to 740°C (1,310°F to 1,360°F) and keep it there for 1 hour per 25 mm (1 inch) of thickness. After that, let it cool down slowly in the furnace, at a rate of 10°C to 20°C (50°F to 70°F) per hour until it hits 600°C (1,110°F), then leave it to cool to room temperature in the air.
Stress Relief Annealing
If you need to relieve internal stresses, heat the steel to 600°C (1,110°F) for regular annealing, or 550°C (1,020°F) for quenching and tempering. Let it stay at that temperature for 1 hour per 50 mm (2 inches) of thickness, and then cool it down slowly in the furnace.
Hardening
- Preheating: Start by preheating the steel to about 450°C to 500°C (840°F to 930°F) for 1 to 2 hours.
- Austenitizing: Then, heat it to 850°C to 880°C (1,560°F to 1,620°F) for the austenitizing process.
- Quenching: Quench the steel quickly in oil, water, or air at 180°C to 220°C (355°F to 430°F). After quenching, the steel should have a hardness of around 50 HRC.
Induction Hardening
1.2312 steel can be induction hardened to increase surface hardness up to 55 HRC. The steel is heated to a temperature of 800°C to 850°C (1,470°F to 1,560°F) using high-frequency induction coils, followed by rapid cooling with water or air.
This process is ideal for parts that require wear resistance on the surface, such as tooling components or shafts while maintaining a tough core. Unlike traditional hardening, which affects the entire piece, induction hardening only targets the surface, providing high precision and efficiency.
Tempering
After quenching, temper the steel by heating it to 180°C to 220°C (355°F to 430°F). Keep it there for 1 hour per 25 mm (1 inch) of thickness. It’s best to temper it twice to make sure the hardness is evenly spread. After tempering, the hardness should be around 280 to 330 HB
Here is a table that shows the hardness of 1.2738 steel in tempered condition at various tempering temperatures:
| Tempering Temperature (°C) | Tempering Temperature (°F) | Hardness (HRC) |
| 100°C | 212°F | 51.5 HRC |
| 200°C | 392°F | 50.2 HRC |
| 300°C | 572°F | 48 HRC |
| 400°C | 752°F | 46.2 HRC |
| 500°C | 932°F | 43 HRC |
| 600°C | 1,112°F | 39 HRC |
| 700°C | 1,292°F | 29 HRC |
1.2738 Tool Steel Applications
With excellent machinability and surface finish, 1.2738 is ideal for producing molds that require precision and durability. Its common applications include:
- Injection Molds: For plastic components in automotive, electronics, and consumer goods.
- Die-Casting Molds: Ideal for aluminum, zinc, and magnesium alloy casting.
- Extrusion Dies: Used for producing plastic, rubber, and metal profiles.
- Mold Inserts: For cores and cavities in injection and compression molds.
Tailored Solutions for 1.2738 Tool Steel
At SteelPRO Group, we offer expert processing services for 1.2738 Tool Steel, including custom machining, cutting, polishing, and heat treatment like tempering and hardening.
With our precision and experience, we ensure your steel is optimized for high-quality molds and components. We also provide 1.2344 Tool Steel for more demanding high-heat applications.
