Can 440C be machined easily?

It is harder to machine than lower-carbon steels, but machinability improves in the annealed condition.

Is 440C stainless steel corrosion resistant?

It has moderate corrosion resistance, but less t han 304 or 316, so it is not suitable for marine environments.

Why is 440C used for knives and bearings?

Because it provides high hardness, wear resistance, and good edge retention.

Stainless Steel 440C

Material Type：Metal
Material Name：Stainless Steel 440C
Alternative Names：UNS S44004 | EN 1.4125 | ASTM A276
Process Compatibility：CNC Milling, CNC Turning, Heat Treatment, Grinding

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Description

440C Stainless Steel is a high-carbon martensitic stainless steel known for its exceptional hardness and wear resistance after heat treatment. With 16–18% chromium and around 1.0% carbon, it achieves the highest strength, hardness, and wear performance among all stainless steels. However, its corrosion resistance is lower than austenitic grades, so it is mainly used in applications requiring high strength, edge retention, and abrasion resistance.

Lead Time:	< 10 days
Wall Thickness:	0.75 mm
Tolerances:	±0.005″ (±0.125mm)
Max Part Size:	200 cm x 80 cm x 100 cm

Classification of Metal Performance Parameters

Mechanical Properties	Ultimate Tensile Strength	1900
	Yield Strength	1310
	Young’s Modulus / Elasticity	200
	Elongation at Break	2
	Hardness	HRC 60
	Fatigue Strength	600
Physical Properties	Density	7.7
	Corrosion Resistance	Moderate
	Magnetism	Magnetic
	Weldability	Poor
	Impact Toughness	Low
Thermal Properties	Maximum Service Temperature	425
	Thermal Expansion Coefficient	10.1
	Thermal Conductivity	24
	Creep Resistance	Low
Electrical Properties	Electrical Resistivity	60
	Electrical Conductivity	2
	Dielectric Strength	N/A
Processing & Surface Treatment	Machinability	Poor
	Surface Finish Compatibility	Fair
	Formability	Poor
Special Properties	Biocompatibility	No
	Flame Retardancy	Yes
	UV Resistance	Low
	Recyclability	Yes

Introduction to Stainless Steel 440C

What

Stainless Steel 440C (UNS S44004) is a high-carbon stainless steel that can be hardened to Rockwell C 58–60 through heat treatment. It combines moderate corrosion resistance with outstanding hardness and edge-holding capability. Its high carbon content makes it similar to tool steels but with the added benefit of stainless properties. It is magnetic in all conditions and widely chosen for bearings, cutlery, and high-precision mechanical components.

Advantages

Can be heat-treated to very high hardness (up to HRC 60)
Excellent wear and abrasion resistance
Good dimensional stability during hardening
Suitable for cutting tools and precision bearings

Applications

Knife blades and surgical instruments
Bearings and valve components
Molds and dies
High-wear mechanical parts

FAQ

Q Can 440C be machined easily?

A
It is harder to machine than lower-carbon steels, but machinability improves in the annealed condition.
Q Is 440C stainless steel corrosion resistant?

A
It has moderate corrosion resistance, but less t han 304 or 316, so it is not suitable for marine environments.
Q Why is 440C used for knives and bearings?

A
Because it provides high hardness, wear resistance, and good edge retention.

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Stainless Steel 440C

Introduction to Stainless Steel 440C

FAQ

Q Can 440C be machined easily?

Q Is 440C stainless steel corrosion resistant?

Q Why is 440C used for knives and bearings?

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