Elevate Your Engineering with Aobo Steel’s 440C Stainless Steel

Discover Unmatched Durability and Corrosion Resistance Now

In the medical field, 440C is widely used for manufacturing surgical knives and other medical instruments. It is also used in the industrial field to manufacture corrosion-resistant plastic and rubber molds. Thanks to Aobo Steel’s abundant and stable supply chain, we not only provide tool steel but also have a strong supply capability in the stainless steel sector. In this field, we still maintain the advantage of factory prices and continuously provide customers with high-quality 440C stainless steel. We offer both 440C round bar and 440C plate shapes.

440C stainless steel applications

Bearings and Bushings: Its high hardness and wear resistance make it suitable for rolling element bearings, races, and bushings, which require high wear resistance.

Valve and Pump Components: 440C stainless steel is used in this field due to its good wear resistance.

Cutting Tools: 440C is a popular choice for high-quality knife blades, cutlery, surgical instruments, chisels, daggers, and razor blades. It is very sharp when processed into blades and has strong corrosion resistance. 440C knives are common in everyday life.

Molds and Dies: 440C’s wear resistance makes it useful in molds and dies that must withstand repetitive use and maintain their shape. Based on our experience at Aobo Steel, 440C material is highly productive in mold applications. Material 440C is an excellent stainless steel mold material, prized for its corrosion resistance and non-stick properties.

Measuring Instruments: The dimensional stability and wear resistance of 440C make it suitable for manufacturing precision measuring instruments.

Why choose Aobo Steel as your supplier

We offer over 100 types of steel, including tool steel, alloy steel, stainless steel, alloy structural steel, and carbon steel.

We provide free cutting services.

With over 40 processing suppliers surrounding us, we have the capacity to deliver more than 2,000 tons of steel per month.

440C stainless steel overview

440C steel is a type of steel under the American steel standard system, with a chromium content as high as 16% to 18%. Because of its strong corrosion resistance and toughness, 440C was initially widely used as raw material for surgical instruments and in the shipbuilding industry. When the carbon content of 440C steel reaches 1.2%, its corrosion resistance is optimized.

Currently, 440C is extensively utilized in the high-end knife market, offering superior strength and sharpness compared to ATS-34. 440C’s weakness includes a gummy texture during grinding and rapid heat buildup. However, 440C is easier to grind than any carbon steel.

440C steel Chemical Composition

Carbon (C)	Chromium (Cr)	Manganese (Mn)	Silicon (Si)	Molybdenum (Mo)	Phosphorus (P)	Sulfur (S)
0.95 – 1.20	16.0 – 18.0	1.00 max	1.00 max	0.75 max	0.040 max	0.030 max

440C Physical property

Property	Value
Density	7.7 g/cm³
Hardness, Rockwell C (HRC)	58-60 (After Heat Treatment)
Tensile Strength, Ultimate	760 MPa (annealed) – 1900 MPa (heat treated)
Tensile Strength, Yield	415 MPa (annealed) – 1800 MPa (heat treated)
Modulus of Elasticity	200 GPa
Poisson’s Ratio	0.3
Electrical Resistivity	0.060×10^-6 Ω⋅m
Thermal Conductivity	24.2 W/m⋅K
Specific Heat Capacity	460 J/kg⋅K
Thermal Expansion Coefficient	10.1 x10^-6 /K (at 20-100°C)
Melting Point	1482-1538 °C
Magnetic Permeability	Yes (Ferromagnetic)

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Benefits of 440C Steel

High hardness (58-60 HRC) and strength for durable tools.
Good corrosion resistance from 16-18% chromium.
Excellent wear resistance due to 0.95-1.20% carbon.
Tough, resists breaking when heat-treated.
Used in knives, aerospace bearings, and medical tools.

440C steel equivalents DIN 1.4125 and JIS SUS440C

Under the German and Japanese steel standard systems, 440C steel is equivalent to DIN 1.4125 and JIS SUS440C, respectively.

1.4125 steel Chemical composition

Carbon (C)	Chromium (Cr)	Molybdenum (Mo)	Manganese (Mn)	Silicon (Si)	Phosphorous (P)	Sulphur (S)
0.95 – 1.20	16.00 – 18.00	0.40 – 0.80	0.0 – 1.00	0.0 – 1.00	0.0 – 0.04	0.0 – 0.03

1.4125 Physical Property

Property	Value
Density	7.65 g/cm³
Thermal Expansion	10.1 x10^-6 /K
Modulus of Elasticity	200 GPa
Thermal Conductivity	24.2 W/m.K
Electrical Resistivity	0.6 x10^-6 Ω .m

SUS440C steel Chemical composition

Carbon (C)	Chromium (Cr)	Molybdenum (Mo)	Manganese (Mn)	Silicon (Si)	Phosphorous (P)	Sulphur (S)	Nickel (Ni)
0.95 – 1.20	16.00 – 18.00	0.0 – 0.75	0.0 – 1.00	0.0 – 1.00	0.0 – 0.04	0.0 – 0.03	0.0 – 0.60

SUS440C Physical Property

Property	Value
Density	7.65 – 7.80 g/cm³
Modulus of Elasticity	200 GPa / 29.008 KSI
Thermal Conductivity	24.2 W/m.K / 168 BTU in/hr.ft².°F
Thermal Expansion	10.2 µm/m°C / 5.67 µin/in°F / 10.2 x10^-6 /K
Melting Point	1483°C / 2700°F
Hardness (Annealed)	269 HB max
Hardness (Hardened)	58-62 HRC
Electrical Resistivity	0.6 x10^-6 Ω .m