440 Stainless Steel
440 stainless steel, also commonly referred to as “razor blade steel,” is a type of hardenable high-carbon chromium steel. This alloy is known for its exceptional hardness and ability to hold a sharp edge, making it a popular choice for razor blades and other cutting tools.

420 Stainless Steel
440 Stainless Steel, also as known as “razor blade steel,” is hardenable high-carbon chromium steel.
One of the unique characteristics of 440 stainless steel is its ability to undergo heat treatment to achieve varying hardness levels.
This gives OEMs the ability to alter the alloy’s properties to meet the unique requirements of their application.
After being strengthened using this method, type 440 steel becomes the hardest stainless steel.
Type 440 steel excels in high-stress settings because of its superior wear and corrosion resistance and high carbon content.
Due to its simplicity in machining, it is the best option for the fabrication of intricate objects.Type 440 steel, which combines strength, toughness, and hardness, is regarded as a top-performing alloy in a variety of industries.
440 Stainless Steel Properties and Specifications
440 offers good corrosion resistance along with abrasion resistance. All grades can be easily machined in their annealed state, they also offer resistance to mild acids, alkalis, foods, fresh water, and air. Type 440 can be hardened to Rockwell 58 harness.
- 440 stainless steel is hardenable high-carbon chromium steels designed to provide stainless properties with maximum hardness.
- Have maximum hardness together with high strength and corrosion resistance in the hardened and stress relieved condition.
- Always used in the hardened or hardened and stress relieved conditions.
- None of the alloys has its full corrosion resistance either in the annealed or in the hardened and tempered condition.
- Wide applications where good corrosion resistance along with high hardness or abrasion resistance is required.
Type 440 Stainless Steel is available in:
- Bar
- Wire
- Billets
The following specifications are generally applicable:
Sheets and Plates
- AMS 5630C
- ASTM A276-67
- ASTM A314-63
- ASTM A-580-67
- QQ-2-763D
- MIL-S-862B
What is 440 Stainless Steel?
High-carbon chromium steel alloy 440 stainless steel is renowned for its excellent toughness and capacity to maintain a sharp edge, this has earned it the term ‘razor steel’.
As a result, it is a preferred option for ball bearings, valve components, surgical and dental equipment, woodworking tools, razors, and blades.
440 is especially known for having a lot of strength and tenacity, making it the go-to steel for use in high-stress situations.
Its high carbon content offers it good wear resistance and corrosion resistance, and it may be heat treated to varied levels of hardness.
It is a preferred choice for intricate parts and components in many sectors and industries since it is relatively simple to process.
History of 440 Stainless Steel
The 1940s saw what could be termed ‘the 440 stainless steel era‘ with the 440A, the first grade of 440, being created as a more effective substitute for the conventional 304 and 316 grades of stainless steel that were in popular use. The 440A grade was renowned for its excellent resistance to corrosion and capacity to maintain a sharp edge, hence the name ‘razor steel’.
The 440B and 440C grades, which have a higher carbon content, were created in the years that followed to offer even more strength and wear resistance. These grades were employed in a wide range of products, including cutlery, medical equipment, ball bearings, and more.
Due to its remarkable performance qualities, the 440 series of stainless steel immediately gained popularity and it was widely employed in the production of a range of products.
Applications for 440 Stainless Steel
440 stainless steel, also known as “razor blade steel,” is a versatile and highly sought-after alloy due to its exceptional hardness and ability to hold a sharp edge. It also has excellent corrosion resistance and high strength and toughness, which makes it suitable for a wide range of applications, particularly in the aerospace, automotive, and medical industries.
With the ability to tailor its properties through heat treatment, it can also be used in a variety of different applications, including manufacturing complex parts and components.
Knife making
Surgical instruments
Oil and Gas
Aerospace and Automotive
Sporting goods
Industrial equipment
Composition & Properties
Property
Type 440C
Carbon
.95 – 1.2
Manganese
1.25 max
Silicon
1.00 max
Phosphorus
.04 max
Sulfur
.04 max
Chromium
16.5 – 18.0
Molybdenum
75 max
Nickel
NA
Mechanical Properties
Properties
Annealed
Hardened & Stress Relieved
Ultimate Tensile Strength (psi)
110,000
285,000
0.2% Yield Strength (psi)
65,000
275,000
Elongation (% in 2?)
14
2
Reduction in area (%)
25
10
Rockwell Hardness
B97
C57
Impact Strength (Izod, V-Notch) [ft-lbs]
NA
1-5