What is 440A stainless steel?
440A steel is a martensitic stainless steel known for its great combination of hardness, wear resistance, and good corrosion resistance, making it popular for knife blades, surgical tools, and bearings, offering superior edge retention and durability compared to basic stainless steels. It has less carbon than its 440B and 440C relatives, giving it the best corrosion resistance in the 440 family, but slightly lower hardness, while still achieving high hardness (around 56-59 HRC) after heat treatment.
440A equivalent material
440A stainless steel (AISI 440A, SAE 51440A, UNS S44002) is a high-carbon martensitic stainless steel known for its high hardness. Its equivalent grades include AMS 5631/5632, ASTM A276, QQ-S-763, and Japan's SUS440. It is used in the manufacture of knives, valves, bearings, and medical instruments, offering both corrosion resistance and excellent edge retention.
| AISI 440A | AMS 5631 | AMS 5632 | ASTM A276 | ASTM A314 |
| ASTM A473 | ASTM A511 | ASTM A580 | QQ S763 | SAE 51440A |
| FED QQ-S-763 | MIL SPEC MIL-S-862 | SAE J405 (51440A) |
440A stainless steel Chemical Composition
| Element | Content (%) |
|---|---|
| Iron, Fe | Balance |
| Chromium, Cr | 16-18 |
| Manganese, Mn | 1 |
| Silicon, Si | 1 |
| Molybdenum, Mo | 0.75 |
| Carbon, C | 0.60-0.75 |
| Sulfur, S | 0.03 |
| Phosphorous, P | 0.04 |
440A stainless steel Mechanical Properties
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength | 725-1790 MPa | 105000 - 260000 psi |
| Yield strength (@strain 0.200 %) | 415-1650 MPa | 60200 - 239000 psi |
| Modulus of elasticity | 204 - 215 GPa | 29600 - 31200 ksi |
| Elongation at break (in 50 mm) | 5- 20% | 5- 20% |
| Hardness, Rockwell B | 95 | 95 |
Possible alternative grades to 440 stainless steels
|
Grade |
Reasons for choosing 440C |
|
440A/B |
Slightly softer and more corrosion resistant grade needed |
|
440F |
High machinability required, with same hardness and hardenability as 440C |
|
420 |
Lower strength and hardness needed than any of the 440 grades |
|
416 |
Higher machinability required, and the much lower hardness and strength is still adequate |
What is the hardness of 440A stainless steel?
After proper heat treatment, 440A stainless steel can achieve a high hardness, typically around 55-58 Rockwell C (HRC). Some sources indicate its standard maximum hardness can reach 56 HRC, while maintaining optimal toughness. Therefore, it exhibits excellent wear resistance and is suitable for applications such as knife blades and surgical instruments.
What are the differences between 440A and 440C stainless steel?
The main difference between 440A and 440C lies in their carbon content. 440C has a significantly higher carbon content than 440A (0.95-1.2% vs. 0.6-0.75%), making 440C harder, more wear-resistant, and capable of holding a sharper edge for longer. 440A, on the other hand, prioritizes corrosion resistance and ductility, is easier to sharpen, but is softer and not suitable for heavy-duty use. In short, 440A is suitable for economical kitchen knives, while 440C is used for high-end, more durable blades.
What are the equivalent grades of 1.4116 stainless steel?
1.4116 steel is a German martensitic stainless steel, most commonly known as X50CrMoV15 (EN standard), equivalent to AISI 420MoV, and sometimes considered a variant of AISI 440A. Other equivalent grades include Chinese 5Cr15MoV and various GOST/NF standards.
What are the differences between 440A and EN 1.4116 stainless steel?
440A and EN 1.4116 (X50CrMoV15) are similar high-carbon martensitic stainless steels, but 440A focuses on corrosion resistance with lower carbon (0.60-0.75%), while 1.4116 adds Molybdenum (Mo) and Vanadium (V) for enhanced wear resistance and hardness (around 54-59 HRC), making 1.4116 generally better for edge retention in knives, though 440A offers superior corrosion resistance due to higher carbon/chromium balance for stainlessness, used often in kitchenware.
GNEE currently has 440A stainless steel in stock, including plates, sheets, coils, strips, tubes, bars, and wires. In addition, we offer a variety of surface finishes to choose from, such as No. 1, 2B, 2D, BA, No. 3, No. 4, HL, No. 8, sandblasting, etc.
We guarantee 100% quality. We will never deliver any defective products to our customers. Please feel free to contact us to customize your required product specifications, including shape, condition, surface treatment, and processing techniques.
