440 Stainless Steel

440 Stainless Steel, also as known as “razor blade steel,” is hardenable high-carbon chromium steel.

440 stainless steel

440 Stainless Steel, also as known as “razor blade steel,” is hardenable high-carbon chromium steel.

Type 440 attains the highest hardness of all stainless steel. This lends itself to applications such as high-quality knife blades, razor blade, high-grade woodworking tools such as chisels, surgical and dental instruments, valve components, and ball bearings.

All 440 steel is hardenable, meaning they gain additional strength via heat treatment, and they are considered a high carbon alloy steel. When strengthened using this process, 440 steel is the hardest of all the stainless steel.

440 Stainless Steel Properties and Specifications

440 Stainless Steel 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, freshwater, and air. Type 440 can be hardened to Rockwell 58 harness.

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  • 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
  • Used in numerous applications in areas where a very hard & abrasion-resistant stainless is called for.
  • Applications include pivot pins, dental and surgical instruments, cutlery valve parts, ball bearings, nozzles, hardened steel balls, seats for oil well pumps, and valve parts.

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